“What’s the solution?”
Chemical Sciences
Year 7
This unit has been developed to meet the needs of Year 7 teachers. It is currently
in draft form. Any feedback via the Moodle is appreciated.
http://dlb.sa.edu.au/pmssmoodle/
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Year 7 Science Units – Draft
Science: Year 7 Unit – Chemical Science
“What’s the Solution?”
Australian Curriculum
Achievement Standard
By the end of Year 7, students describe techniques to separate pure substances from mixtures. They represent
and predict the effects of unbalanced forces, including Earth’s gravity, on motion. They explain how the relative
positions of the Earth, sun and moon affect phenomena on Earth. They analyse how the sustainable use of
resources depends on the way they are formed and cycle through Earth systems. They predict the effect of
environmental changes on feeding relationships and classify and organise diverse organisms based on observable
differences. Students describe situations where scientific knowledge from different science disciplines has
been used to solve a real world problem. They explain how the solution was viewed by, and impacted on,
different groups in society.
Students identify questions that can be investigated scientifically. They plan fair experimental methods,
identifying variables to be changed and measured. They select equipment that improves fairness and
accuracy and describe how they considered safety. Students draw on evidence to support their conclusions.
They summarise data from different sources, describe trends and refer to the quality of their data when
suggesting improvements to their methods. They communicate their ideas, methods and findings using
scientific language and appropriate representations
Science Understanding
 Mixtures, including solutions, contain a combination of pure substances and can be separated using a range of
techniques
Science as a Human Endeavour
 Science and technology contribute to finding solutions to a range of contemporary issues; these solutions may
impact on other areas of society and involve ethical implications
 Science understanding influences the development of practices in areas of human activity such as industry,
agriculture and marine and terrestrial resource management
 People use understanding and skills from across the disciplines of science in their occupations
Science Inquiry Skills
 Identify questions and problems that can be investigated scientifically and make predictions based on
scientific knowledge
 Collaboratively and individually plan and conduct a range of investigation types, including fieldwork and
experiments, ensuring safety and ethical guidelines are followed
 In fair tests, measure and control variables, and select equipment to collect data with accuracy appropriate to
the task
 Construct and use a range of representations, including graphs, keys and models to represent and analyse
patterns or relationships, including using digital technologies as appropriate
 Summarise data, from student’s own investigations and secondary sources, and use scientific understanding to
identify relationships and draw conclusions
 Reflect on the method used to investigate a question or solve a problem, including evaluating the quality of the
data collected, and identify improvements to the method
 Use scientific knowledge and findings from investigations to evaluate claims
 Communicate ideas, findings and solutions to problems using scientific language and representations using
digital technologies as appropriate
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Links to General Capabilities
Literacy
The interdependence of science and literacy is demonstrated throughout this unit as students engage in a variety
of different literacies of science. The language and literacy demands specific to the study of science develop along
with scientific understanding and skills. This unit provides opportunities for students to develop their literacy
skills as they:
 Engage in discussions and record their thinking, ideas and questions in journals
 Draw labelled diagrams
 Read texts and procedures
 Present their information in an appropriate visual or oral format
 Complete visual representations of their understandings
Numeracy
Within this unit students engage in tasks involving practical measurement and the collection, representation and
interpretation of data from investigations. This unit provides opportunities for students to develop their
mathematical understanding in the following ways:





Discuss measurements used in the recipe?
Discuss ratio and where would you use it?
Convert to make larger quantities? E.g. enough for 20 people, 100, 1000 etc
Measuring liquids with accuracy and precision
Gathering, recording and presenting data from investigations (both primary and secondary data)
Information and Communication Technology (ICT) Competence
Within this unit students information technologies are used to research a science concept and present their
understandings. Communication technologies offer opportunities for the communication and sharing of students’
ideas and results both within and beyond the classroom. This unit provides opportunities for students to develop
their ICT skills in the following ways:



Use digital photographs to present their understandings
Use of computers for research purposes
Presentation of information - flow diagram, separation toolkit
Critical and Creative Thinking
Within this unit students are asked to pose questions, make predictions, solve problems through investigation,
analyse and evaluate evidence and summarise information. Students plan and conduct practical investigations.
Students are asked to think in new ways about observations of the world. This unit provides opportunities for
students to develop their critical and creative thinking skills in the following ways:



Developing a separation toolkit
Developing a strategy for separating different materials
Presentation of understandings – flow chart and information poster
Ethical Behaviour
Ethical behaviour is relevant to experimental science and the use of scientific information. Within this unit
students apply ethical guidelines in the gathering of evidence, including, considering the implications of their
investigation on others, the environment and on other living organisms. This unit provides opportunities for
students to develop their ethical behaviour in the following ways:



Working as part of a team on an investigation
Gathering evidence to support their claims
Working safely with equipment
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Personal and Social Competence
Within this unit students further develop their teamwork skills by working together, sharing ideas and discussing
their work. They develop self management skills such as planning effectively, following procedures and working
safely. This unit provides opportunities for students to develop their personal and social competence in the
following ways:
 Working together in teams to complete tasks such as filling in tables, organising and conducting
investigations
 Working with others to develop strategies to separate materials and then successfully present their
results
Links to Cross-Curriculum Priorities
Sustainability
Sustainability is concerned with the ongoing capacity of the Earth to maintain life. It aims to reduce our ecological
footprint while simultaneously supporting a quality of life that is valued – the ‘liveability’ of our society. Scientific
understanding and scientific inquiry processes help students to appreciate how people forecast change and plan the
actions necessary to shape more sustainable futures, including the design, construction and / or management of the
physical and social environment. This unit provides opportunities for students to develop an understanding of
sustainability in the following ways:
 Investigation into a variety of separation techniques and how these may impact on society e.g. water
filtration, recycling, wetlands, desalination plant
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Chemical Science
Unit at a glance
Phase
ENGAGE
Lesson
At a glance
Lesson 1
Session 1
Thinking About Mixtures and
Solutions
To capture students’ interest and find
out what they think they know about mixtures
and solutions and how they can be separated
Session 2
Everyday Mixtures and Solutions
Lesson 2
Making sherbet
EXPLORE
Lesson 3
Separation Around Us
To provide opportunities for students to
explore separation techniques used in their
everyday lives
Lesson 4
Exploring Separation
To provide hands on, shared experiences of
different separation techniques.
Lesson 5
Serial Dilution
EXPLAIN
To provide hands on, shared experiences of
different concentrations of solutions
Lesson 6
Understanding the Key Words
To support students in their development of
their understanding of the key words
Lesson 7
Separation Toolkit
ELABORATE
Lesson 8
Separating the Mess
EVALUATE
Lesson 9
Session 1
Practical Applications
To enable students to demonstrate their
understanding
of
different
separation
methods.
To provide opportunities for students to
demonstrate their knowledge of and ability to
perform different separation techniques.
To provide opportunities for students to
investigate real life applications of separation
techniques
Session 2
Practical Applications
Lesson 10
Demonstrating the Understanding
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To provide opportunities for students to
represent what they know about solutions,
mixtures and separation techniques
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Year 7 Science Units – Draft
What’s the Solution?
ENGAGE
Lesson 1
Session 1: Thinking About Mixtures and Solutions
At a Glance:
To find out what students think they know about solutions, mixtures and different methods of separation
Assessment Focus:
Diagnostic Assessment is an important aspect of the Engage phase. This lesson will elicit what students
already know and understand about solutions and mixtures and possible ways to separate them. This allows
teachers to take into account students’ existing ideas when planning future learning experiences.
Assessment Opportunities: Diagnostic Assessment
 Participation in discussions
 Journal entries
 Completed questions
Science Outcomes:
Students will be able to:
 Record their current understanding of mixtures, solutions, reversible and irreversible changes and
different separation techniques
Literacy Outcomes:
Students will be able to:
 Contribute to discussions
 Use written text to record their experiences and current understandings
Session 1: Thinking About Mixtures and Solutions
Equipment for each student:
 A copy of Resource Sheet 1 – Mixtures and Solutions
Teacher background information
A pure substance is a substance that cannot be separated into other substances by any physical processes.
It will have a constant chemical composition. Water and gold are examples of pure substances. Pure water
(H20) is made up of 2 hydrogen atoms and 1 oxygen atom which are chemically bonded. This composition
does not change. Pure gold (Au) only contains gold atoms. Pure substances are homogenous – they have
uniform composition throughout the whole sample. Elements and compounds are both examples of pure
substances.
Elements are pure substances that cannot be broken down into simpler substances. Some examples of
elements are oxygen (O), hydrogen (H), helium (He), iron (Fe) and calcium (Ca).
Compounds are pure substances made up of two or more elements. Some examples of compounds are water
(H2O), carbon dioxide (CO2), sodium chloride (salt - NaCl) These can only be separated into individual
elements through a chemical process.
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ENGAGE
A mixture is when two or more substances are mixed together and there is no
chemical change. Mixtures are substances held together by physical forces and not chemical ones. Each of
the substances in a mixture keeps its original chemical properties. Mixtures can usually be separated back
to the original components using a variety of techniques. Examples of mixtures include sand and water, a
mixed salad, salt water, a bag of assorted nails etc. The composition of a mixture can be varied by changing
the proportion of the substances that make it up.
Solutions are also mixtures. A solution is a type of mixture where one substance is dissolved in the other.
In solutions the substance that dissolves will, over time, become evenly distributed throughout. E.g a
solution of sugar and water means the sugar is evenly distributed throughout the water.
If we compare sugar and water to sand and water – both are a type of mixture. The sugar dissolves and is
evenly dispersed throughout the water while the sand sinks to the bottom. The sugar and water mixture is
a solution while the sand and water mixture is not a solution. Solutions can also be gases dissolved in a
liquid such as carbonated water found in fizzy drinks. In this case, the carbon dioxide (CO2) is evenly
distributed throughout the water, making it a solution. The bubbles that we see in fizzy drinks are not part
of the solution; rather they are the carbon dioxide that has separated from the solution and been released
as gas.
Scootle Links:
TLF ID L3198 – Elements, compounds, mixtures and solutions
TLF ID L5822 - Types of matter: pure substances and mixtures
TLF ID L5824 - Types of matter: compounds and mixtures
Preparation
Photocopy Resource Sheet 1 for each student
Prepare a version of a TWLH chart
Literacy Focus:
A TWLH chart is used to elicit
beliefs and ideas about a topic
before, during and after an
investigation or experience. It
includes four sections with the
headings: What we Think we know,
What we Want to know, What we
Learned, and How we Know.
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Lesson outline
Key words: solution, mixture, separation, reversible and irreversible changes
1. Introduce the key questions: What are mixtures and solutions and why might they need to be
separated? What techniques can be used in the separation process? Explain that these are the
questions students will be focussing on throughout the unit. Put these questions on display and
continually refer back to them whilst working through other activities within this unit.
2. Organise the students into groups of three and give each student a copy of Resource Sheet 1 –
Mixtures and Solutions. Explain to the students that you are attempting to find out what their
current understandings around mixtures and solutions are. Ask each team to discuss their thoughts
on the questions and then have them individually record their understandings on the sheet.
3. Meet together as a class to share some of the responses and complete the relevant sections of the
TWLH chart -What we think we know and what we want to know. At this stage it is not about having
the correct understanding it is about identifying the students’ current understandings.
Teacher tip:
If students are unclear about reversible and irreversible changes you may need to briefly revisit
this idea as this idea is assumed knowledge from the year 6 science curriculum.
It would also be beneficial to incorporate these concepts into discussions throughout the unit as a
way of revising previous learning and putting such learning into other contexts.
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Matter: Mixtures and Solutions
Name ___________________________
Date _________
Please record your individual responses to the following in as much detail as possible.
What is a mixture?
What is a solution?
What are some of the ways mixtures can be separated?
What do you understand by the terms reversible and irreversible changes?
Give some examples to support your thinking.
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Resource Sheet 1
Year 7 Science Units – Draft
Session 2 – Everyday Mixtures and Solutions
At a Glance:
To capture students’ interest and find out what they think they know about
solutions, mixtures and methods of separation.
ENGAGE
Assessment Focus:
Diagnostic Assessment is an important aspect of the Engage phase. This lesson will elicit what students
already know and understand about mixtures and solutions and possible ways to separate them. This allows
teachers to take into account students’ existing ideas when planning future learning experiences.
Assessment Opportunities: Diagnostic Assessment
 Participation in discussions
 Journal entries
Science Outcomes:
Students will be able to:
 Use their current understandings to start identifying mixtures and solutions
 Engage in discussions about whether or not mixtures and solutions can be separated
 Begin to identify different separation techniques
Literacy Outcomes:
Students will be able to:
 Contribute to discussions around science
 Use written text to record their experiences and current understandings
Session 2: Everyday Mixtures and Solutions
Equipment for teacher :
 PowerPoint presentation (this is the only equipment needed if you are showing the PowerPoint)
 OR A variety of different household liquids and powders (safe for students to use – see
preparation for further details)
 Clear plastic cups
 Two buckets – one is for the mixtures and solutions to be poured into; the other is for the dirty
cups
Equipment for the class:
 Class science journal (optional)
 TWLH Chart
Equipment for each student:
 Science journals
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Teacher Background Information
Dissolve: When something dissolves it forms a solution in a solvent. When you add
ENGAGE
sugar (solute) to water (solvent) the sugar mixes with the water and a solution is
formed. When the sugar enters the water the sugar molecules break away from the sugar crystal and
dissolve into the solution of water molecules. The sugar and water molecules begin to mix. The two
substances continue to mix with each other until the sugar is evenly distributed throughout the water and
a solution is formed.
Sugar enters the water
Water and sugar molecules
begin to mix
Sugar is evenly distributed
Sugar is made up of molecules. The forces between each molecule are weak forces while the forces within
the molecules are very strong. This means that when sugar is placed in water the molecules separate from
each other. The molecules themselves stay in tact.
A molecule is a group of two or more atoms that stick together. When two hydrogen atoms combine with
one oxygen atom we get a water molecule. All water is made of tiny water molecules.
Not all substances dissolve in the same way. Some compounds such as salt (NaCl) are ‘ionic’ in nature. This
means that when they dissolve, they break into ions (charged atoms or groups of atoms) rather than
complete molecules. The water causes the sodium and chloride atoms from the salt to separate. It forms a
solution containing separate sodium ions (Na+) and chloride ions (Cl-). When the process is reversed and the
water is removed the sodium ions and the chloride ions rejoin to make a salt crystal.
Preparation
Organise access to the PowerPoint – ‘From This to This’. This PowerPoint can be located on the moodle http://dlb.sa.edu.au/pmssmoodle/ under the chemical science unit OR you could bring in a variety of
different powders and liquids from your kitchen cupboard. Eg milo, milk, water, soft drink, flour, cereal,
rice, food colouring, vinegar, bicarb soda, cordial etc.
If you are using substances from the kitchen to undertake this activity you will also need access to an
empty bucket to tip out any mixtures and solutions when you have finished and a bucket to place the dirty
cups into ready for washing.
Safety Note: You may need to complete a risk assessment on some of the materials you are
using. Be aware of the potential hazard of vinegar being splashed into student’s eyes. If using vinegar
ensure you have access to water.
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Lesson outline
Key words: substance, mixture, solution, dissolve, separation, pure substance
ENGAGE
Using the PowerPoint
1. Revisit part of the key questions: What are mixtures and solutions?
2. Place the students in cooperative learning teams and then introduce the PowerPoint – “From This to
This” - to the class (title slide only) and ask them to brainstorm a list of the different mixtures and
solutions that they use in their homes.
3. Move through the PowerPoint one slide at a time and ask students to make predictions in their
cooperative learning teams about what they think will happen when the two substances are mixed.
Are any of the substances they are using pure substances? Do they think mixing them together will
result in a solution or a mixture? Could the two substances then be separated? Discuss predictions
with students before moving to the next slide which shows the two substances when they are mixed
together.
4. On completion of the slide show ask students to look back at the original lists of other substances
used around the home that are commonly mixed together. Is there anything else they can add to this
list? Share suggestions with the class and discuss which of these form a solution and which of these
form a mixture? Which of them can be separated?
5. Update information on the TWLH Chart.
OR
Using the materials from the kitchen
1. Revisit part of the key questions: What are mixtures and solutions?
2. Place students in cooperative learning teams and let them look at the different substances you have
brought in. Ask them to discuss which substances they think can be combined to make a mixture and
which substances they think can be combined to make a solution. Are any of the substances they are
working with pure substances? Have them record their thinking as lists in their science journals.
3. Meet together as a class group and ask students to share their predictions regarding mixtures and
solutions. As students offer a suggestion about what may make a mixture or solution, combine those
substances together to check their predictions. As a class discuss whether or not they think the
mixture or solution could be separated and what strategies might be used.
Teacher Tips
At this stage if you are using actual materials for this lesson it is suggested that you run the session
as a demonstration only. You could ask individuals to come out and demonstrate particular
combinations but students get plenty of opportunities to “use” the materials themselves at a later
stage. This will alleviate the mess and the need for lots of materials at this early stage.
4. On completion ask students to think of any other examples of mixtures or solutions that could be
found around the home.
5. Update information on the TWLH Chart.
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Lesson 2: Sherbet
ENGAGE
At a Glance:
To capture students’ interest and find out what they think they know about solutions and mixtures and
methods of separation.
Assessment Focus:
Diagnostic Assessment is an important aspect of the Engage phase. This lesson will elicit what students
already know and understand about mixtures and solutions and possible ways to separate them. This allows
teachers to take into account students’ existing ideas when planning future learning experiences.
Assessment Opportunities: Diagnostic Assessment
 Participation in discussions
 Ability to follow a simple procedure
 Journal entries
Science Outcomes:
Students will be able to:
 Use their current understandings to talk about mixtures and solutions
 Follow a simple scientific procedure
 Engage in discussions around science concepts and explanations
Literacy Outcomes:
Students will be able to:
 Contribute to discussions about the science behind the sherbet
 Use written text to record their experiences and current understandings
Lesson 2: Sherbet
Equipment for the class:
 Class science journal (optional)
 Word Wall and Glossary
Equipment for each team:
 Role badges for Director, Manager and Speaker
 Each team member’s science journal
 Access to citric acid, bicarb soda and icing sugar
 Measuring cup and spoon
 Clean plastic cup for mixing
 Clean popsticks for tasting
Equipment for each student:
 Science journals
 Copy of the procedure (Resource Sheet 2)
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Teacher background information
ENGAGE
Sherbet fizz
The ingredients in the procedure are listed under their common names. You may like to introduce students
to the scientific names of some of these ingredients:
Bicarb soda – sodium bicarbonate
Icing sugar – sucrose
Citric acid – citric acid (this is the acid that makes lemons and limes sour)
When you initially combine the ingredients to make the sherbet you have created a mixture. There has
been no chemical change and each of the substances has maintained its chemical properties. They will not
react with each other while they are dry. The fizz from the sherbet occurs when an acid (citric acid) and
an alkaline (the bicarbonate soda) combine with the saliva in the mouth. The water in the saliva allows the
citric acid and the bicarbonate soda to dissolve. As they mix together to form a compound a chemical
reaction occurs and they create a gas (carbon dioxide) in the form of lots of tiny bubbles. You are actually
feeling the sensation of carbon dioxide bubbles on your tongue. These are the same bubbles that are in
fizzy drinks. The icing sugar adds the sweetness to the sherbet; it is not part of the chemical reaction.
Preparation
Distribute the ingredients into smaller containers so all students have easier access.
Lesson Outline:
Key words: solution, mixture, dissolve, compound
1. Give each student a copy of the ‘Making Sherbet’ Resource Sheet 2. Take time to read through the
procedure and check for student understanding. Discuss what is meant by 5 parts to 1 part. What will
this look like?
2. Show the students the equipment and ingredients provided. Then allow them the time to follow the
procedure to make their own sherbet.
3. Engage in a whole class discussion around the sherbet:
 Is it a mixture or a solution?
 What is the role of each of the ingredients? What would happen if you left one out?
4. Discuss what happens scientifically when the sherbet is placed on the tongue. Record discussion
points in journals.
Literacy focus
A science journal is a record of observations, experiences and reflections. It contains a series of
dated, chronological entries. It may include written tests, drawings, labelled diagrams, photographs,
tables and graphs.
Teacher Tips
 Be prepared for a mess.
 Encourage students to initially follow the procedure and not just ‘mix’ things together.
 Provide students with a zip lock bag so they can take home any uneaten sherbet. This alleviates
the need for them to eat it all in one go.
Eating too much sherbet can make students feel sick.
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Opportunities for Extension
Are all three ingredients necessary? Ask students to predict what would happen if one of the ingredients
were removed. This could be the focus of a class discussion or it could be investigated by students by
making three different versions of the sherbet. (Each version with a different ingredient missing).
Possible Curriculum Links
Numeracy – Why didn’t the recipe include specific amounts? Or did it? How do you know how much of each
ingredient to use? Discuss the concept of 5 parts to one. What might this look like? What measurements
might you use? How much of each ingredient will you need? What is ratio and where else might you use it?
How much of each ingredient would you need if you were making enough sherbet for 30 students? 100
students? The whole school?
Literacy – students could be asked to write:
 An explanation of what they think happens to the sherbet mixture when it is placed in the mouth.
 A recount of the lesson.
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Making Sherbet
(Make sure you use clean, dry equipment)
INGREDIENTS

Icing sugar

Citric acid

Bicarbonate soda

Cup

Measuring spoon / teaspoon

Popstick for sampling sherbet
PROCEDURE
Add 5 parts icing sugar, 1 part citric acid & 1 part bicarbonate
soda
Stir ingredients together
Place a small amount on your tongue.
After tasting you may need to make some changes. If it is too
bitter add more sugar. If there isn't enough fizz you may need
to add more bicarbonate soda or citric acid. (Make sure you only
add small amounts at a time, remember you can always add more
but it is very hard to take it away.)
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Resource Sheet 2
Year 7 Science Units – Draft
Lesson 3: Separation Around Us
EXPLORE
At a Glance:
To provide opportunities for students to explore separation techniques used in their everyday lives.
Assessment Focus:
Formative Assessment is an important aspect of the Explore phase. It involves monitoring students’
developing understanding and giving feedback that extends their learning.
Assessment Opportunities: Formative Assessment
 Participation in discussions
 Initial classification of photographs
 Journal entries on different separation techniques
 Response to question
Science Outcomes:
Students will be able to:
 Classify photographs according to different separation techniques using current understandings
 Engage in discussions around their understanding of different separation techniques
 Explain how different separation techniques help to find solutions to problems
Literacy Outcomes:
Students will be able to:
 Contribute to discussions about separation techniques
 Use written text to record their experiences and current understandings
Lesson 3: Separation Around Us
Equipment for the class:
 Class science journal (optional)
 Word Wall and Glossary
Equipment for each team:
 Role badges for Director, Manager and Speaker
 Each team member’s science journal
 Package of separation photos
Equipment for each student:
 Science journals
Preparation
The photos for this lesson are stored in the Chemical Science folder on the Moodle. There are both high
and low resolution copies of the photos - http://dlb.sa.edu.au/pmssmoodle/
Organise enough copies of the separation photos so that each cooperative learning team has a set of their
own to work with.
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Lesson Outline:
Key words: separation, filtering, decanting, evaporating, sieving, visual separation
EXPLORE
1. Organise students into cooperative learning teams. Revisit the key question – ‘What techniques can
be used in the separation process?’ Ask each team to consider their responses to this question.
2. Discuss the following question: What are some of the different processes you have used or seen used
to separate items?
3. Provide each team with a copy of the separation photos and ask them to work together to sort the
photos into different groups according to their own criteria. When they have sorted all the photos
into groups have them record the criteria they used for sorting on a piece of paper and turn that
piece of paper upside down and place it alongside the groups.
Teacher note: At this stage it is about students using their own criteria and being able to explain
the reasoning behind their choices. There are no right or wrong ways to classify the photos.
As a form of assessment students could take digital photos of their classified photos and use these
as a way of recording their prior understandings about separation.
4. Once all teams have finalised their classifications and recorded their criteria for classification allow
students to walk around and view the groupings of others. They can look closely at the different
groups that have been organised and try to work out the criteria used for classification. Once they
think they know how the photographs were sorted they can turn over the piece of paper which has the
criteria written on it to see if their thinking was correct.
5. Meet together as a class to discuss the different criteria used and the ways in which the objects
were grouped. What problems are solved by the different separation techniques? E.g. nets have been
used to solve the problem of birds taking fruit from trees. The nets are used to separate the birds
from the fruit.
6. Go through the photographs as a class group and create a list of the different separation techniques
that were represented.
 Which of the photographs demonstrated a form of decanting? Sieving? Filtering? Visual
separation? Magnetism? Other?
 Which were hard to classify? Why?
 How did you finally decide where to put them?
 Can you think of any other examples that could have been used?
7. Have students answer the following question – “How has using these separation techniques made our
lives easier?” Record their current understanding and thinking in their journals. They can use
examples from the photographs to support them in this process. Ask them to add information to the
TWLH chart.
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Lesson 4: Exploring Separation
EXPLORE
At a Glance:
To provide hands on, shared experiences of separation techniques.
Assessment Focus:
Formative Assessment is an important aspect of the Explore phase. It involves monitoring students’
developing understanding and giving feedback that extends their learning.
Assessment Opportunities: Formative Assessment
 Participation in discussions
 Completion of record sheet (Resource Sheet 4)
 Journal entries
Science Outcomes:
Students will be able to:
 Explore a variety of separation techniques
 Make predictions and observations
 Engage in discussions around different separation techniques and their understanding of what is
happening
Literacy Outcomes:
Students will be able to:
 Contribute to discussions about separation techniques
 Use written text to record their experiences and current understandings
 Record observations and predictions in a table format
Lesson 4: Exploring Separation
Equipment for the class:
 Class science journal (optional)
 Word Wall and Glossary
 Bins for the removal of waste – one for liquid waste, one for solid waste and one for the collection of
dirty equipment
 Containers of sand, talcum powder, iron filings, marbles, salt, rice, flour etc
 Spoons – one or two per container
 Magnets – in a zip lock bag (see teacher tip)
 A variety of materials for filtering – paper towel, filter paper, muslin etc
 A variety of sieves with different sized holes
 Jugs of water
 Tweezers, tongs
 Information for each of the separation techniques (Resource Sheet 3). Cut into individual separation
techniques
 TWLH Chart
Teacher Tip:
Place each magnet inside a zip lock bag or wrap them in a layer of glad wrap. This makes the removal of
the iron filings from the magnet easier when the lesson is completed.
If you have access to ‘Flowers of Sulfur’ (local high school chemistry lab) this could also be used
as it will float when mixed with water and can then be decanted. Risk assessment required.
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Equipment for each team:
 Role badges for Director, Manager and Speaker
 Each team member’s science journal
 Container of base material – sand
 Plastic cups and plates (at least 6 of each)
 Paper towel for cleaning up spills
 A list of the different separation techniques available to them (Resource Sheet 3)
EXPLORE
Equipment for each student:
 Science journals
 A copy of Resource Sheet 4
Teacher background information
Decanting
Decanting is when you separate a liquid from an insoluble solid by carefully pouring the liquid from the
container leaving the sediment behind. E.g. draining vegetables, decanting wine to remove the sediment,
separating sand and water, panning for gold. It is the density of the solid compared to the liquid that is the
property that enables you to decant. The solid or denser particles sink to the bottom and the water can
then be poured off.
Visual separation
Visual separation is when materials can be separated by hand due to the differences
in size and appearance with other substances in the mixture. The substances are
easily identified between each other and can be easily separated by hand. Eg.
Separating rocks and leaves, marbles from sand. It is the colour, size and shape
which is the important property used for this type of separation.
Magnetic separation
Magnetic separation is when magnetic material is removed from a mixture using a
magnetic force. The magnetic material is attracted to the magnet and leaves the
other non magnetic substances behind. Eg separating paper clips from sand, metal
materials from the recycling bins. It is the magnetic features of the material which
enables it to be separated in this way.
Sieving
Sieving is when you separate different substances by using a sieve. Mixtures of
different sized particles are separated by passing the mixture through a device
containing many small holes. The holes allow the smaller particles to pass through
trapping the larger particles in the container. Sieving is generally used when you
have a mixture with reasonable sized particles. Eg separating macaroni from
water, removing lumps from flour. It is the size of the particles which is the
important property when sieving.
Filtering / filtration
Filtering is when you separate materials based on the size of the particles by passing
the mixture through material (generally paper) which allows the smaller particles to
pass through and traps the larger ones. Filtering is generally used in place of sieving
when you are dealing with particle sizes that are much smaller and would easily pass
through the holes in a sieve, Eg separating dirt from water, flour and water. It is the
size of the particles which is the important property when filtering.
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EXPLORE
Year 7 Science Units – Draft
Evaporation
Evaporation as a separation technique is a method in which water can be converted
from its liquid form to its vapour / gas form. E.g. drying the clothes, separating salt
and water, sugar and water, dirt and water. Although evaporation enables you to
separate the two substances it does not allow you to capture the water. It simply
leaves the residue behind.
Chromatography and distillation are other forms of separation which are not being covered in this unit.
The following links provide visual demonstrations of different separation techniques which could be used to
support the learning.
http://www.youtube.com/watch?v=cs6iJavFJiI – magnetic separation separating nails from wood chips
http://www.youtube.com/watch?v=2yRWCanU0kM&feature=related – separating aluminium cans, steel cans, paper and
plastic
http://www.youtube.com/watch?v=-dljgJqj9H8&feature=related - separating waste materials
http://www.youtube.com/watch?v=qZ0nNWODNTg&NR=1 – roll sand sifter
Preparation
 Photocopy Resource Sheet 3 and cut up into separate pieces. These pieces will be used as labels to
identify the different equipment provided for each separation technique used in the exploration
process. You will also need another copy of this page for each cooperative learning team. This copy
does not need to be cut up.

Photocopy Resource Sheet 4. Students may need two copies of this page.
Teacher Tip:
Resource Sheet 4 may be better photocopied as an A3 sheet as it will give the students more room to
record their thoughts.

Organise equipment at the front of the classroom so it is easily accessible for all students. Place all
the separation tools and equipment together under the appropriate heading. E.g. put all of the
different sieves in the one spot along with the sieve information from Resource Sheet 3.

Place buckets / bins around the room so students have easy access for the removal of waste
materials which will help keep their work spaces tidy. Clearly label the bins.
– One bin for liquid waste
– One bin for solid waste
– One bin to place dirty equipment for cleaning at a later time

Organise the substances the students will need into small containers that are easily accessible. Have
four or five containers of each substance so students can take them back to their desks, use what
they need and then return what is left when they have finished with it.
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Year 7 Science Units – Draft
Lesson Outline:
Key words: separation, filtering, decanting, evaporating, sieving, visual separation,
magnetic separation
EXPLORE
1. Organise students into cooperative learning teams and assign roles. Revisit the key unit questions What are mixtures and solutions and why might they need to be separated? What techniques
can be used in the separation process? Explain to students that they are going to be exploring
different mixtures and solutions and looking for ways to separate them.
2. Provide each student with a copy of the lesson recording sheet (Resource Sheet 4) and model the
way the lesson will be structured. Ask the students to fill in the information about the first two
substances based on the demonstration that you provide.
Teacher tip:
You can use any substance as the base material. Use a substance that is readily available and easy to use.
For this lesson we have chosen to use sand as the base material for students to work with.
To help keep a clean work space and catch accidental spillages students can conduct their separation
techniques within the lid of an A4 paper box or into the bottom of a low plastic container. Plastic ice
cream containers are also ideal. That way if anything is spilt it can be easily contained and cleaned up.
Structure of the investigation using sand as the base material
Teacher Demonstration
– Decide which of the available materials you are going to combine with the sand. Before combining
the materials ask the students to complete the relevant section of the recording sheet. Then ask
them to record what they think will happen when you combine the sand with the other substance
(this is their prediction).
– Combine the two substances and let the students observe what happens. Ask them to record their
observations on the recording sheet.
– Discuss the techniques available for separation with the class and then decide which of those they
think may be best for separating the two substances and which of those would not help.
– Choose two of the different techniques and demonstrate how you would go about trying to
separate the substances using these two techniques. Ask the students to record their
observations of what happened as you go.
– Then get the students to make a decision, based on their observations, on which of the two
separation techniques was the most effective. What evidence did they base their decision on?
Record their thoughts on the recording sheet.
– Throw the liquid and solid materials into the identified waste bin and then place the dirty
equipment into another bin for cleaning. It is important to talk with students about maintaining a
clean, organised work space.
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Year 7 Science Units – Draft
Students Investigation
EXPLORE
3. Once you have modelled the structure of the investigation explain to the
students that they are now going to repeat this process by combining the
base material with the other materials provided. Give them the time needed to work with their team
to complete the table using the other materials.
4. When students have finished combining their base material with the other substances ask them to
meet with someone else from the class and share their responses. They can compare their
responses and opinions about which separation technique works best for which materials and which
separation techniques do not work. Repeat this process once more so that students have met with
two other people to discuss their thinking.
5. Glue record sheets into journals and then meet together as a class to share questions, responses,
findings. Briefly look at the different separation techniques: What did it separate well? What did it
have trouble separating?
6. Update information on the TWLH Chart.
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Year 7 Science Units – Draft
Visual Separation
When materials can be separated by hand from other
substances in the mixture due to the differences in size and
appearance.
Magnetic Separation
When magnetic material is removed from a mixture using
a magnetic force.
Sieving
Separation of a mixture of different sized particles by passing
the mixture through a device containing many small holes.
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Resource Sheet 3
Year 7 Science Units – Draft
Filtering
Separation of a mixture of different sized particles by
passing the mixture through material (generally paper)
that allows the smaller particles to pass through and
traps the larger ones.
Evaporation
When water is converted from its liquid form to its vapour
form.
Decanting
Carefully pouring the liquid from a container leaving the
sediment behind. Separating a liquid from an insoluble solid.
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Resource25Sheet 3
Year 7 Science Units – Draft
EXPLORING THE SEPARATION OF MATERIALS – Base Substance_________________________
Substance
Prediction - What do you think will
happen when the two substances are
combined?
Will the substances form a
solution or a mixture? Explain
your thinking
Separation techniques – Which
two methods will you use for
separation? Which do you think
will work best? Why?
Record your observations
Record your observations
Record your observations
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Resource Sheet 4
Year 7 Science Units – Draft
Results – Which method worked
best? How do you know?
Lesson 5: Saturated Solution to Dilution
EXPLORE
At a Glance:
To provide hands on, shared experiences of different concentrations of solutions
Assessment Focus:
Formative Assessment is an important aspect of the Explore phase. It involves monitoring students’
developing understanding and giving feedback that extends their learning.
Assessment Opportunities: Formative Assessment
 Participation in discussions
 Recorded observations
Science Outcomes:
Students will be able to:
 Engage in discussions around the dilution and concentration of solutions
 Follow a scientific procedure
 Use key scientific terms appropriately
Literacy Outcomes:
Students will be able to:
 Contribute to discussions
 Record their observations and thoughts in an appropriate format
Lesson 5: Saturated Solution to Dilution
Equipment for the class:
 Class science journal
 TWLH Chart
Equipment for each team:
 5 plastic cups
 Measuring cylinder
 400ml of plain water
 ½ cup of salt
 Teaspoon
 Measuring cup or cylinder
 Food colouring
Equipment for each student:
 A copy of the procedure (Resource Sheet 5)
 Science journals
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Year 7 Science Units – Draft
Teacher background information
EXPLORE
A solute is dissolved in a solvent. The solute is the substance to be dissolved and
the solvent is the substance that does the dissolving.
A serial dilution enables you to make different concentrations of the same solution. You create a series
of dilutions where each one is progressively weaker than the one before. The dilution at each step is
constant.
In a mixture the components can be found in different proportions. Solutions are a type of mixture and
can therefore be found in different concentrations from a concentrate through to a very dilute solution.
A dilute solution is a solution that only has a small amount of solute dissolved in the solvent. You can make
solutions more dilute by adding more solvent.
A concentrated solution is where there is a high proportion of solute in the solvent. For example orange
juice concentrate has had a lot of the water removed and needs this water returned to make the solution
drinkable. The water is the solvent and the orange juice is the solute.
A saturated solution is a solution where the maximum amount of solute has been dissolved. There is no
room for anymore of the solute. If you continuously add salt to water you will reach a point where no more
salt will dissolve and the salt will start to settle on the bottom of the glass. This is a saturated solution.
If you increase the temperature of the water it will allow more salt to dissolve but even that will
eventually reach saturation point. A saturated solution is not necessarily a concentrated solution as it may
be a solution that becomes saturated at a low concentration.
When you combine cordial and water you are diluting a solution. The cordial is already a solution so when
you place it in water you dilute it further. You increase the amount of solvent.
Preparation
Photocopy Resource Sheet 5 so that there is enough for one per student.
Teacher Tip:
If you want your students to explore saturated solutions then make sure you use salt in this activity.
Adding food colouring to the solution will give the students a visual indicator of the dilution process.
This task can also be done using plain water and food colouring or plain water and cordial. If you use
either of these two options you are not able to link it to saturated solutions.
Lesson Outline:
Key words: solution, dilute, solvent, solute, soluble, insoluble, mixture, pure substances, saturated
solution, concentrate
1. Organise students into cooperative learning teams and assign the necessary roles.
2. Make sure all teams have a plastic cup and easy access to salt in order to create their saturated
solution. Ask them to place 150ml of water in their plastic cup.
3. Explain to the students that they are going to find out how much salt can be dissolved in 150ml of
water. Have them predict how many level teaspoons of salt they think can be dissolved in 150ml of
water.
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Year 7 Science Units – Draft
4. Discuss what is meant by a level teaspoon and how will students know
when no more salt will dissolve? Get the students to investigate how much
salt will dissolve in the water.
EXPLORE
5. Compare results from the class and suggest possible reasons for any differences. (Inconsistencies
in measuring – water and salt, stirred or not stirred, inaccurate counting). Explain to students that
they have now created a saturated solution. Discuss briefly what is meant by a saturated solution.
Is there any way that more salt could be added? Introduce the words solute and solvent. Identify
the solute and solvent from the saturated solution they made. Place this solution to one side.
6. Read the instructions on the back of a cordial container and make a sample of cordial following the
instructions precisely. Discuss what happens to the cordial when you mix it with the water. Is it a
solution or a mixture? How do you know?
7. Ask them to organise themselves into a line according to the strength of cordial that they like to
drink – very strong through to very weak. Engage in a class discussion about what is meant by the
words very strong? How do you define strong cordial? How do you define weak cordial? What is
meant by a concentrate? What other things may need to be diluted before use.
8. Ask students to discuss what is meant by the word dilute and how do you make solutions more or
less dilute? Explain to the students that they are about to complete a serial dilution procedure
using the saturated solution they made earlier. Discuss what they think this means and what they
think they will have to do to complete the process.
9. Give each student a copy of Resource Sheet 5. Ask them to read through the procedure and
identify parts they are not clear about. Discuss these sections. Read through the procedure with
the class and then allow them the time to complete the procedure in their cooperative learning
teams.
10. Ask them to photograph / record observations about each of the four cups and record their
thoughts and observations in their science journals.
– What do they notice about each cup of liquid?
– Can they work out what has happened mathematically?
– What would the concentration of the next cup be if they continued the process?
11. Meet together to share responses and observations. Add any new information to the TWLH chart.
Teacher tip:
Students can use a portable salinity meter (Refractometer) to measure the salt concentrations of the
different solutions. Salinity meters (Refractometers) can be purchased for $70 from the DECS
Science Equipment Scheme. Item number - Code: 21-070. www.bizgate.sa.gov.au/shop/decs/ They are
easy to set up and students can clearly and easily read the concentration of salt in a solution.
Optional
Link the lesson to the salinity levels of water. Collect some different water samples for testing. –
Distilled water, tap water, sea water, bottled water, river water (from different locations) etc. How does
the salinity level vary in different water samples? What are acceptable levels of salinity in our water?
Curriculum Links:
Maths / Numeracy
What is ratio? Can you create a cordial mix with a 1:1 ratio? What quantities of each substance would you
need? What about a 1:2 ratio? 1:4? What is meant by one part cordial to three parts water?
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Year 7 Science Units – Draft
Serial Dilution Procedure
Equipment
4 plastic cups
100ml of the saturated solution made earlier
300ml of tap water
100ml measuring cylinder
Food colouring
Procedure
 Decant the liquid from the saturated solution made earlier and
place 100ml of this liquid into the first plastic cup. Add four or five
drops of food colouring. Stir.




Place 90 ml of tap water into each of the 3 other cups. This water
is the buffer water needed to total the solution back to 100ml
Take 10ml of the solution out of cup 1 and add it to a new cup (cup2)
which contains 90ml of buffer in it. Stir the solution. This will
dilute the solution concentration to one tenth of the original
solution.
Take 10ml of the solution out of cup 2 and add it to a new cup (cup
3) which contains 90ml of buffer in it. Stir the solution. This will
dilute the solution concentration to one hundredth of the original
solution.
Repeat this process once more. The final cup should contain 100ml
of liquid.
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Resource Sheet 5
Year 7 Science Units – Draft
Lesson 6: Understanding the Key Words
EXPLAIN
At a Glance:
To develop an idea of students current levels of understanding of the key words used in the unit and
provide them with the opportunities to increase their understanding.
Assessment Focus:
Formative Assessment is an important aspect of the Explain phase. It involves monitoring students’
developing understanding and giving feedback that extends their learning.
Assessment Opportunities: Formative Assessment
 Participation in discussions around the key words
 Visual representations of the key words
Science Outcomes:
Students will be able to:
 Engage in discussions around the key science words of the unit
 Explain their understanding of the key words
Literacy Outcomes:
Students will be able to:
 Contribute to discussions about key science words
 Create a visual representation of one of the key words
Lesson 6: Understanding the Key Words
Equipment for the class
 A copy of Resource Sheet 6 cut up into individual pieces
 TWLH Chart
 Access to science dictionaries and the internet
Equipment for each student:
 Science journals
Preparation
 Photocopy the words and their definitions. Cut the page into words and definitions. You should have
44 pieces of paper.
Lesson Outline:
Key words: separation, filtering, decanting, evaporating, sieving, visual separation, magnetic separation,
solution, dilute, solvent, solute, soluble, insoluble, mixture, pure substance
1. Ask students to form pairs and then give each student one of the cut up pieces of paper. Be aware
that you will have more words and definitions than the number of students in your class. You may
wish to identify the more important definitions for your class or some students will need to have
two words or definitions. (Make sure the pair does not get an immediate match when you give out
the words and the definitions.) Ask the students to discuss the words or definitions that are on
their pieces of paper.
– What do they think the word means?
– When is it used?
– What word from their learning best matches the definition they have?
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Year 7 Science Units – Draft
2. Once they have had a discussion ask the students to find their matching
partner. E.g. the student who has the word or definition that matches
what they have in their hands.
EXPLAIN
3. When everybody has found their matching partner ask the students to discuss the word they have
and its meaning. Do they understand what it means? When is it used? Can they give some
examples? If students are unsure allow some whole class discussion time for students to clarify
their thinking.
4. Students then need to work with their partner to complete a visual representation of the word and
its meaning.
Literacy Focus:
A visual representation is a pictorial way of representing the meaning of the word. This
representation could be a diagram, a picture, a cartoon, an annotated diagram. It is a way of
visually getting the message across.
5. Display the completed representations around the room and give the students the opportunity to
look at what has been presented by others by completing a gallery walk.
Literacy Focus:
In a Gallery Walk students move from one exhibit to another, using the agreed focus to
discuss / respond to the exhibits. It provides an opportunity for all work to be on show and
students to see the variety of responses provided for the task.
6. This is an ideal opportunity for them to provide feedback to others around the work that has been
completed. As they are going around the room looking at the work of others get them to look
carefully at each representation and identify how successful the representations are at getting
the message across.
–
–
–
Can you clearly work out what the word means from the visual representation?
What have they done well?
What could be done to improve the representation?
7. Students can record their thoughts on sticky notes and place these on the pieces of work. Each
student could be asked to comment on one or two pieces of work.
8. Meet together as a class to share feedback and representations and update information on the
TWLH Chart.
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Year 7 Science Units – Draft
Pure substance
A substance that cannot be separated into other kinds of
matter by physical processes. It has a consistent colour,
taste, texture and composition. It is made out of the same
particles.
Mixture
A combination of two or more ingredients, the particles of
which are separable and independent.
Sediment
Solid matter which settles at the bottom of a liquid.
Solution
A mixture made up of one substance that has dissolved into
another. The solution has the same physical state as the
solvent.
Solute
A substance dissolved in another substance, forming a
solution.
Solvent
A substance, usually a liquid, capable of dissolving another
substance. The solvent is usually the substance that is
present in greater proportion.
Dissolve
To form a solution in a solvent. When you add sugar (solute)
to water (solvent) the sugar mixes with the water and a
solution is formed.
Filtrate
Material, especially liquid, that has passed through a filter.
Soluble
Capable of being dissolved in a solvent.
Element
Pure substances that cannot be broken down into simpler
substances. Some examples are oxygen (O), hydrogen (H),
iron (Fe)
Insoluble
When a substance will not dissolve in a particular solvent.
For example iron filings will not dissolve in water. They are
insoluble.
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Resource Sheet 6
Year 7 Science Units – Draft
Filtering
Separation of a mixture of different sized particles using a
filter, such as paper. The smaller particles pass through the
filter and the larger particles are trapped.
Sieving
Separation of a mixture of different sized particles by
passing the mixture through a sieve containing many small
holes.
Evaporation
One method in which water is converted from its liquid
form to its gas form.
Dilute
A solution with a low concentration of the solute dissolved
in the solvent.
Concentrated
A solution with a high concentration of the solute dissolved
in the solvent.
Compound
A compound is made of two or more elements that are
chemically combined, always in a set ratio.
Suspension
A suspension is a mixture with particles of a solid that will
not dissolve.
Saturated solution
A solution where no more solute can be dissolved at a
constant temperature.
Decanting
Carefully pouring the liquid from a container leaving the
sediment behind. Separating a liquid from an insoluble solid.
Magnetic separation
When magnetic material is removed from a mixture using a
magnetic force.
Visual separation
When materials can be separated by hand from other
substances in the mixture due to the large differences in
size / appearance.
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Resource Sheet 6
Year 7 Science Units – Draft
Lesson 7: Separation Toolkit
EXPLAIN
At a Glance:
To support students to represent their understandings of separation techniques.
Assessment Focus:
Formative Assessment is an important aspect of the Explain phase. It involves monitoring students’
developing understanding and giving feedback that extends their learning.
Assessment Opportunities: Formative Assessment
 Participation in discussions
 Completed page for the toolkit
Science Outcomes:
Students will be able to:
 Engage in discussions around different separation techniques
 Explain their understanding of the different techniques
Literacy Outcomes:
Students will be able to:
 Contribute to discussions
 Present an information page on one of the separation techniques
Lesson 7: Separation Toolkit
Equipment for each student:

Science journals
Preparation
 Photocopy the blank example of a possible layout for a separation toolkit page to show students what
it could look like - Resource Sheet 7.

Photocopy an A3 copy of Resource Sheet 9 and cut it into individual pieces. Have an A3 copy of
Resource Sheet 8 available to piece it back together on. This page has the title of each of the
columns already in place for the students to use as a cue for the information they need to give.

Ensure the different types of separation techniques are available to be displayed around the room
once the brainstorm is completed (Resource Sheet 3). This page was used earlier in the unit.
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Year 7 Science Unit – Draft
Lesson Outline:
Key words: (will vary according to the separation technique students choose to
EXPLAIN
use) separation, filtering, decanting, evaporating, sieving, visual separation,
magnetic separation, solution, dilute, solvent, solute, soluble, insoluble, mixture, pure substance
1. Brainstorm a list of the different separation techniques students can remember. What can they tell
you about each one? As they tell you different techniques and information about them find that
information from the cut up pieces of Resource Sheet 9 and place it in the appropriate place on
Resource Sheet 8. Work as a class to complete all sections of the blank sheet.
2. Place the names of the different separation techniques on individual pieces of paper and place these
inside an envelope. Students then choose a piece of paper from the envelope and this tells them the
separation technique they are going to be working on.
–
–
Students can be given time to negotiate swaps with other people
Students could choose the separation technique that interests them the most
3. Explain to the students that they are about to create a page of information for a separation toolkit.
Discuss the following:
–
What is a toolkit?
–
What things might you find in a toolkit?
–
What are some different types of toolkits?
–
What might you find in a maths toolkit? A mechanics toolkit? A chef’s toolkit?
Brainstorm the information that the students think might be relevant in a separation toolkit.
4. Create a list of information that the students must include in their toolkit page. E.g.
–
A photo of the different equipment you can use
–
An explanation of how it works
–
What sorts of things can be separated using this method?
–
What things cannot be separated?
–
When would you use this method?
–
What are the advantages / disadvantages to this method?
5. Show the students a possible way to present the information (Resource Sheet 7) and allow them the
opportunity to discuss other ideas for presentation that they may have.
6. Give students the time needed to complete their page for the separation toolkit. Each page could be
presented the same way for consistency of information or students could be encouraged to develop
their own presentation style.
7. Completed pages can then be put together to produce separation toolkit booklets or the pages can
be displayed individually around the room.
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Year 7 Science Unit – Draft
EXAMPLE OF POSSIBLE PAGE FOR SEPARATION TOOL
Visual sorting is …..
Visual sorting works best when…….
Visual sorting will not work when…….
Photo(s) demonstrating the visual sorting
separation technique
These are some things that you can easily
visually sort.
Some advantages of using this method.
Primary Mathematics and Science
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Some disadvantages of using this method.
37
Resource Sheet 7
Year 7 Science Unit – Draft
Separation Technique
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Definition
Property Used for
Separation
38
Resource Sheet 8
Year 7 Science Unit – Draft
Example
Separation Technique
Definition
Property Used for
Separation
Example
Filtration
To remove by the act of a filter
Solubility
Dirt and water
Sifting (sieving)
A simple and convenient technique of
separating particles of different sizes.
Particle size
Stones and sand
Carefully pouring a solution from a container
in order to leave the precipitate (sediments)
in the bottom of the original container
Density
Water and sand
Magnetic attraction
(Magnetism)
Attracted to a magnet
Magnetism
Iron filings and sand
Evaporation
To change from a liquid or solid state into
vapour
Solubility and vaporisation
Salt and water
Visual sorting
Sorting by colour, shape or size
Colour, shape or size
Rocks and leaves
Decanting
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Resource Sheet 9
Year 7 Science Unit – Draft
Lesson 8: Separating the Mess
ELABORATE
At a Glance:
To provide opportunities for students to demonstrate their knowledge of different separation techniques
and their ability to perform separations using such techniques.
Assessment Focus:
Summative Assessment of the investigating outcomes is an important aspect of the Elaborate phase. It
involves monitoring students’ developing skills and understandings of the Science Inquiry Skills and the
investigative process.
Assessment Opportunities: Summative Assessment
 Participation in discussions
 Journal entries
 Investigation planner
 Investigation results and conclusions
 Completed procedural text or flow chart
Science Outcomes:
Students will be able to:
 Use their current understandings of separation techniques to solve a problem
 Create a scientific procedure / flow chart for others to follow
 Engage in discussions around science concepts and explain their thinking
Literacy Outcomes:
Students will be able to:
 Contribute to discussions about the science behind their thinking
 Use written text to record their experiences and current understandings
Lesson 8: Separating the Mess
Equipment for the class:
 Class science journal (optional)
 Equipment for different separation techniques – filter paper, water, magnets, containers, sieves,
tweezers etc.
 Bins / containers to throw out liquid and solid waste as needed
 A container to place dirty equipment when finished
 Paper towel, cloths for cleaning mess
 TWLH Chart
 Materials for creating the mess – 1 kg of rice, 1 kg of salt, 2 bags of marbles, 1 kg of sand, 200
grams of iron filings (if you cannot get iron filings substitute another magnetic material e.g. paper
clips)
Equipment for each team:
 Role badges for Director, Manager and Speaker
 An appropriate amount of the combined materials (See teacher preparation notes for details)
 Plastic cups / containers
 Access to water
 Plastic plates
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Year 7 Science Unit – Draft
Equipment for each student:
 Science journals
 Copy of investigation planner and recording sheet (Resource Sheet 10 and
11)
ELABORATE
Teacher background information
One strategy for separating the substances is as follows:
1. Remove the marbles by hand using visual separation as the technique. The marbles can then be
placed to one side.
2. The iron filings can then be removed using the magnetic separation technique. (See teacher tip page
18) Move the magnet through the mixture numerous times and the iron filings will attach themselves
to the magnet and then can be easily removed. The iron filings can then be placed to one side.
3. Use a sieve to remove the rice grains. The mixture may need to be sieved a couple of times
depending on the size of the holes. The rice can then be placed to one side.
4. You are now left with a mixture of salt and sand. To separate these two substances add water to
the mixture and stir it well. The salt will dissolve while the sand will settle at the bottom.
5. The water can then be decanted and filtered through filter paper. This should let the liquid through
and leave any remaining sand behind. Place the sand to one side and leave it to dry.
6. You are now left with a solution of salty water. To separate the salt from the water pour the
solution into a shallow dish (the shallower the better as it will evaporate more quickly). Leave the
solution to evaporate. You should then be left with a small amount of salt.
Do not expect students to be able to separate back to the original quantities of each substance. The
more of the original quantities they can get the better but it would be extremely difficult to get the
original amount back.
The amount of salt returned is very small.
The more water you add to the salt / sand mixture the longer it will take to evaporate.
Preparation
Organise the individual amounts of the substances needed for the task: marbles, sand, iron filings, rice and
salt. The amounts given above are a guide only. You may wish to adapt or modify these amounts to suit the
size of your class. Make sure you include a reasonable amount of salt as this is the hardest substance to
separate.
Ensure students have somewhere they can dispose of any waste materials in order to help them keep a
clean work space. Provide a container for solid waste, one for liquid waste and one for used equipment.
Teacher tip:
To help keep a clean work space and catch accidental spillages have students conduct their separation
techniques within the lid of an A4 paper box or into the bottom of a low plastic container such as an ice
cream container. That way if anything is spilt it can be easily contained and cleaned up.
You can create a mixture using other household ingredients such as flour, sugar, stones etc. You will
need to ensure that the substances can all be separated in some way. For example do not combine sugar
and salt in this mix as it is not possible to separate the two using the equipment and techniques
available.
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Year 7 Science Unit – Draft
Lesson Outline
Key words: separation, filtration, sieving, evaporation, magnetism, visual separation,
solvent, solute, prediction,
ELABORATE
1. Before the break that precedes the science lesson show the students the individual samples of the
different substances they will be working with after the break. – Salt, rice, marbles, iron filings and
sand.
2. When the students go out to the break, combine the substances together into one pile on a table. This
will provide the mixture that the students are required to separate. You will need to prepare enough
mixture to ensure each team has enough to try a variety of procedures. One lot per team is probably
not enough as things will go wrong and they may need to start again with a new batch.
3. When the students return explain to them that somehow all the substances got mixed together. The
lesson has now changed and what they will now have to do is work in cooperative learning teams, using
their knowledge of the different substances and the different separation techniques to separate the
materials.
4. Organise the students into teams and assign roles. Provide each team with a list of the materials that
are in the mixture and a list of the different separation techniques they have been working with over
the last few weeks ( Resource Sheet 12)
5. Give teams time to discuss the processes they think they will use in order to return as much of the
original, individual samples as possible. Have them map out their thinking in their journals – this could be
done as a flow chart or in any way the students’ choose. Then reorganise the class into different groups
and have them share their thinking with others. This is an ideal opportunity for students to compare
ideas, to challenge thinking and to put forward suggestions for improvements.
6. Students then return to their original teams and share any new ideas or thoughts that they may now
have that they think will improve the effectiveness of their separation plan. In teams have students
complete the Investigation Planner (Resource Sheet 10). They need to develop a plan around the order
that they are going to use to separate the substances.
Things to consider
– What separation techniques will you use first? Why?
– What will happen next? Why?
– What will you do if something doesn’t work?
7. Before students begin to implement their plan discuss with them the things they need to consider in
order to keep a safe, clean work environment.
– Clean up any spills immediately
– Put away equipment as you finish with it
– Complete the separation tasks with care
– Use equipment safely and correctly
– Be considerate of others
8. Teams can then begin to work through the processes they have developed to separate the substances.
Make sure the students are aware that they need to record the processes they used and what
happened as a result of these processes at the end of each step (Resource Sheet 11). This becomes a
vital link to the next part of this task.
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Year 7 Science Unit – Draft
9. Students then use the information from the investigation results sheet to
ELABORATE
develop a written procedure around the separation of substances or a flow
chart showing the processes used and the steps they followed.
– A procedural text is used to describe how something is done. It includes a list of materials
needed to complete the task, and a sequence of instructional steps. It may also include
annotated diagrams.
– A flow chart is a graphic organiser used to describe a sequence of events or the stages of a
process. A linear flow chart arranges the information in one line and uses arrows to indicate
the order in which to read the text.
10. Provide students with the opportunity to share their completed procedures / flow charts with other
class members.
11. Students then complete the following evaluation questions in relation to separating the mess.
–
How successful was your procedure? Why?
–
What problems did you face? How did you solve them?
–
What would you do differently next time? Why?
–
What did you find challenging?
–
What surprised you?
12. Update the TWLH Chart
Teacher tip:
If students have not been introduced to procedural texts or done any work around them, it is
critical to give them time to deconstruct procedural texts in other contexts e.g. English lessons
before attempting to write one for science.
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Year 7 Science Unit – Draft
Separation investigation planner
Name:_________________________________________
Date:_______________
Other members of your team:_______________________________________________
What are you going to investigate?
Solve this problem
What equipment will you need?
A group of substances have accidently
been mixed together. Using your
knowledge of different separation
techniques and the properties of
materials try and separate as much of
each of the substances as possible.
Make a list of equipment.
What separation techniques are you going to use and in what order are you going to use
them? Explain why.
You could use a flow chart to help organise your thinking. Record some predictions.
What will you do to ensure a safe working environment?
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Resource Sheet 10
Year 7 Science Unit – Draft
Separation investigation results
Name:_________________________________________
Date:_______________
Use this sheet to record each of the steps that were used to separate the materials. Be sure to also
record the results of each separation and the level of success. (If you need more space use another sheet)
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
Step 7
Step 8
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Resource Sheet 11
Year 7 Science Unit – Draft
Separating the Mess
Contained in the mess you will find:
Sand
Salt
Rice
Iron filings
Marbles
Separation techniques you may use:
Magnetic separation – to separate using magnetic
attraction
Visual separation – to separate by colour, shape or size
Filtering- to separate by using a filter
Evaporation – to separate by allowing a liquid to change
from a liquid into a vapour / gas
Sieving – to separate using a sieve
Decanting – to separate by pouring the liquid from a
container and leaving the sediment behind
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Resource sheet 12
Year 7 Science Unit – Draft
Lesson 9: Session 1
Practical Applications
ELABORATE
At a Glance:
To provide opportunities for students to discuss how science and technology have contributed to finding
solutions to a range of issues.
Assessment Focus:
Summative Assessment of the investigating outcomes is an important aspect of the Elaborate phase. It
involves monitoring students’ skill development and their understandings of the Science Inquiry Skills.
Assessment Opportunities: Summative Assessment
 Participation in discussions
 Written journal entries
Science Outcomes:
Students will be able to:
 Discuss how science and technology have contributed to finding solutions to a range of issues
Literacy Outcomes:
Students will be able to:
 Contribute to discussions
 Use journal entries to record their thoughts
Lesson 9: Session 1
Practical Applications
Equipment for the class:
 One clear container such as a small fish tank or a clear, large plastic bowl containing 4 or 5 litres of
water
 Catchment story labels – see preparation section
 Substances to represent each of the factors entering the river system – see preparation section
 16 small containers to hold materials e.g. foam cups, polycarbonate vials
DECS Science Equipment Scheme.
VIAL, clear polycarbonate, screw
cap, 70mL, 44mm dia x 57mm
high, pack of 50
Vial covered by
paper to hide the
contents from
students.
Code: 60-236
$36 a pack
Teacher Background Information
Water is a precious commodity and a requirement for life. It is essential to our survival. All of us living
within water catchments contribute directly or indirectly to the degradation of our waterways often
without realising the impacts that we make. This places many ecosystems under threat of pollution.
Keeping our water safe for consumption involves science and technology working together to ensure the
pollutants are removed. This involves the use of a variety of separation techniques. It is an excellent
example of how science and technology have contributed to find solutions to an issue.
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Year 7 Science Unit – Draft
Preparation
There are 16 land uses identified in the story. Adapt this to suit the size of your
class. E.g. each land use could be assigned to two people.
ELABORATE
Some land uses could be omitted if they are not relevant to your catchment area. You can also add extra
land uses if they are of relevance to your local region. This is a decision that can be made at individual
sites.
Organise one labelled container / vial for each of the things that are to be placed in the river during the
story. See list below for substances. You do not need large amounts of each of the substances.
Catchment Story Substances
Land Use
Ingredient
Power station
Vinegar (acid rain)
Herd of cattle
Thick muddy water
Fertiliser
Baking powder
Piggery
Thick muddy water
Grazing land
Salty water
Coal Mine
Vinegar (acid runoff)
Hobby farms
Yellow water / toilet paper
Fishing
Tangle of line
Water skiing
Vegetable oil
Park
Styrofoam, plastic etc
Tourism
Paper, plastic etc
Subdivision
Soil
Gardens
Baking soda (pesticide)
Roads
Vinegar (acid runoff)
Industry
Soapy water
Tannery
Red food colouring
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Year 7 Science Unit – Draft
Catchment Story labels (to be placed on containers)
Set 1
Power Station
Herd of Cattle
Farming Country
Piggery
Grazing Land
Coal Mine
Hobby Farms
Fishing
Water Skiing
Park
Tourism
Subdivision
Gardens
Roads
Industry
Tannery
Power Station
Herd of Cattle
Farming Country
Piggery
Grazing Land
Coal Mine
Hobby Farms
Fishing
Water Skiing
Park
Tourism
Subdivision
Gardens
Roads
Industry
Tannery
Set 2
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Resource Sheet 13
Year 7 Science Unit – Draft
Session Outline
Key words: separation, filtration,
separation, solvent, solute
sieving,
evaporation,
magnetism,
visual
ELABORATE
1. Introduce the concept that Australia is the driest inhabited continent and that water is a precious
commodity that is essential to our survival. Ask students to think about a local waterway or river
system (or one such as the Murray - Darling system that is an important waterway for a large
proportion of Australians) Discuss how what they do in their lives may impact on a local waterway or
river system.
2. Place the fish tank or clear large container containing four or five litres of water in the middle of
the class and explain that this represents the river.
3. Distribute the smaller containers amongst the class and explain to them that you are going to read a
story and when their ‘character’ emerges in the story they need to empty their container into the
‘river’.
4. Read the story to the students, (Resource Sheet 14) stopping at the end of each section when a
character / land use is mentioned. At this point ask the particular student(s) to come forward and
empty their container into the ‘river’.
5. Ask the students to get into small groups to discuss the following questions:
– What were they feeling / thinking as the different substances were being added to the water?
– Do they think this is like a real situation?
– What practices are in place / should be in place to ensure minimal pollution to our river systems?
– How could the science they have been learning about contribute to the cleaning of the river?
– What separation processes could be useful in this situation?
6. Meet together as a class to share thoughts around how the science of separation techniques and
mixtures and solutions links to the story they have just heard. What are some of the possible ways
to ‘clean up the water’? After the discussion ask students to record their thoughts around the
following - How has science and technology contributed to finding solutions to water pollution? What
other possible solutions do you have to help this situation?
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THE STORY OF A RIVER
This is the story of the travels of a very special river - our river through its catchment. It begins in the higher parts of the catchment
where the rain runs off the slopes and begins its long journey to the sea.
In the valley below there is a power station which generates electricity
for the region. It burns large quantities of coal and releases pollutant gases into the atmosphere.
These pollutants combine with moisture in the atmosphere to produce acid rain. Rainfall carries
these acids back to the Earth's surface and can pollute the very source of the river. The water
gathers momentum as it descends the slopes. The river continues its journey towards the sea
through farming country where, recently, some crops were fertilised. Afterwards they were
watered and the run-off into the river has brought with it some of the fertiliser.
The neighbouring farm is a piggery. Some of the manure from the pig pens washes into a drainage
pipe which then empties into the river. On the other side of the river are grazing lands. There
are very few trees remaining and in some of the lower parts of the pasture, the water table has
risen because the trees are not using the water any more. This water brings the salts in the soil
up to the surface making the land unusable. It also means that run-off from the land is salty and
this threatens the freshwater organisms and animals in the river. A grazing herd of cattle feed
on the vegetation on the banks. When heavy rains arrive the banks collapse into the river.
The coal mine, which supplies raw mineral for the power station, pumps water out of the river to
clean its equipment and flush out some of the waste. This includes various acids which all drain
back into the river. Slowly the river starts to wind its way through the outskirts of a major town.
Out here there are a number of hobby farms. The houses here are not connected to a sewerage
system but have their own septic tanks. Occasionally these tanks overflow and untreated sewage
seeps directly into the river.
There are a number of people making use of the river around the bend. Someone is fishing on the
banks. Unfortunately their line gets caught around a rock and is left in the water. Other people
are water-skiing. Their boat needs a service and in the meantime its engine is leaking oil directly
into the river. Another group of people is enjoying a picnic at a park overlooking the river. A gust
of wind blows some of their rubbish off the table and down into the water.
Further downstream the river is being utilised for tourism. A charter boat is giving some people a
scenic tour of the river. Drinks are for sale on board but not everyone uses the bins that are
provided.
The river now starts to meander through the suburban part of the town. A new subdivision is
being developed. Many of the trees have been removed and when it rains, the top layer of soil is
eroded and contributes to the silting up the river. Most houses in the developed parts of the town
have a garden. To keep those nasty bugs away the gardeners use a range of pesticides. At the end
of the day the sprinklers are turned on to water the plants. The pesticides wash off into the
stormwater drains and enter the river.
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Resource Sheet 14
Year 7 Science Unit – Draft
People who have spent the day at work are now starting to drive home. The roads are choked with
traffic. Oil drips out of many of these cars and sometimes they brake in a hurry leaving traces of
rubber on the road. Every time it rains these pollutants are carried into the stormwater drains
and straight into the river.
There is still some industry along the river here. It uses detergents to keep its production
equipment clean. But sometimes, the dirty water is hosed out of the factory into the gutter where
it disappears into a storm water drain. Once again, however, this water flows straight into the
river. If there were phosphates in the detergent then it will cause excess algae growth in the
river. When this algae dies and begins to rot, it uses up oxygen which animals in the water rely on.
They may suffocate as a result.
Redevelopment is occurring on the opposite bank. Demolishers have discovered a few drums of
something mysterious. They won't be able to sell these as scrap. Someone suggests emptying them
into the river. Everyone agrees and the waste from the old tannery is released into the river, to
the detriment of all the organisms and animals living in it.
With one final bend the river finally arrives at its mouth and flows into the sea. But look at what
flows out with it!
Adapted with permission from Queensland Waterwatch – http://qld.waterwatch.org.au
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Resource Sheet 14
Year 7 Science Unit – Draft
Lesson 9: Session 2
Practical Applications
ELABORATE
At a Glance:
To provide opportunities for students to investigate real life applications of separation techniques.
Assessment Focus:
Summative Assessment of the investigating outcomes is an important aspect of the Elaborate phase. It
involves monitoring students’ developing skills and understandings of the Science Inquiry Skills and the
investigative process.
Assessment Opportunities: Summative Assessment
 Participation in discussions
 Journal entries
 Oral presentation of research
Science Outcomes:
Students will be able to:
 Engage in discussions around the application of different separation techniques
 Discuss how science and technology have contributed to finding solutions to a range of issues
Literacy Outcomes:
Students will be able to:
 Contribute to discussions about their findings
 Research and organise information
 Deliver an oral presentation on their research findings
Lesson 9: Session 2
Practical Applications
Equipment for the class:
 A3 pages for each industry
Equipment for each pair:
 Individual science journals
 Copy of Resource Sheet 15
Teacher background information
Wastewater treatment plants
The purpose of wastewater treatment plants is to process wastewater so it is not dangerous to humans or
the environment. Wastewater consists of a mixture of domestic sewage (waste from toilets, sinks, showers
and washing machines), industrial waste and occasional run-off surface water which has made its way into
the sewers. Treatment plants use several processes, both physical and chemical to treat the wastewater.
During the initial stages screens are used to remove the course solids such as paper and plastics. After
this has occurred the flow of the waste is reduced to encourage sedimentation. Sedimentation occurs when
the heavier particles settle due to gravity on the bottom of the tank. The settled solids are scraped from
the bottom and the surface of the liquid is skimmed to remove any floating materials.
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Bacteria and other microorganisms are then introduced. Some of the remaining
ELABORATE
solid matter is processed by these microorganisms to form clumps of material
which can then be skimmed. The microorganisms are then removed from waste
materials usually through sedimentation or filtration. Chemical processes are then used to remove any
heavy metals.
http://www.sawater.com.au/SAWater/Education/OurWastewaterSystems/Wastewater+Treatment+Process.htm
Scootle Link: TLF ID L3103 – Explore a water treatment plant
Desalination plant
The desalination process removes dissolved salts and impurities from seawater and turns it into quality
drinking water.
The most commonly used process for desalination is reverse osmosis. Reverse osmosis involves pushing sea
water through very fine membranes at extremely high pressure. The membranes act as filters to remove
the salt and impurities.
http://www.environment.gov.au/soe/2006/publications/emerging/desal/index.html
http://www.sawater.com.au/SAWater/WhatsNew/MajorProjects/ADP.htm
http://www.waterforgood.sa.gov.au/desalination/the-adelaide-desalination-plant/
Water treatment plants
For many years Adelaide relied on drinking untreated water from the River Murray. Water from South
Australia’s reservoirs is now treated to improve the quality of our water and make it suitable for drinking.
The processes involved in water treatment plants are the very similar to the processes that are used to
treat wastewater.
Water undergoes a 5 stage cleaning process.
The first stage is known as coagulation and flocculation and is used to collect small particles and dissolved
organic matter. This stage is a complex process where coagulants are added to the water. These coagulants
react with the impurities in the water causing them to form larger particles up to 5mm in diameter. This is
known as flocculation.
The second part of the process involves sedimentation. Once the water leaves the flocculation tanks it
passes into the sedimentation basins where the water is left to settle. The floc settles to the bottom and
forms a sludge which is later removed.
Once sedimentation has occurred the water is then filtered. It is passed through a deep bed of sand. As
the water filters through the sand the particles left from the sedimentation process are removed.
When the water has passed through the filters it still needs to be made safe for human consumption. This
is achieved by adding chlorine to the water to destroy any micro-organisms that were not removed through
the previous processes.
After the water has had the chlorine added it is then stored in covered storage tanks ready to be
distributed.
http://www.sawater.com.au/SAWater/Education/OurWaterSystems/Water+Treatment+Plants.htm
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Year 7 Science Unit – Draft
Recycling centres
Waste materials that are sent to recycling centres are separated in a variety of
ways.
ELABORATE
Visual separation – material that is large or easily recyclable is removed by hand, cans, bottles, plastics are
separated by workers manually removing these items and placing them in different areas.
Other recyclables travel along sorting lines which is a process that uses a combination of machines and
people to sort materials into specific areas. Different people have different responsibilities along this line.
Magnets are used to separate ferrous metals
http://www.wingfieldrecycling.com.au/
Wetlands
Wetlands are an important way to help improve our water quality. Within the wetlands environment there
are several different separation techniques at work.
Floating and semi submerged litter is separated from the water in one of two ways. It is either trapped by
the trash racks (gross pollutant traps which operate like large sieves, allowing the water through but
trapping the rubbish) or it is trapped by the plants growing within the wetland where it can later be
removed by hand (visual separation)
As water moves slowly through a wetlands environment sedimentation occurs. This is where the heavier
particles of mud and silt and other pollutants sink to the bottom of the wetlands. Due to this
sedimentation sections of wetlands may need dredging over time.
http://waterwatchadelaide.net.au/index.php?page=how-does-a-wetland-work
http://science.howstuffworks.com/environmental/green-science/wetland.htm
Mining industry
Magnetic separation is used to remove large ferrous metals that could be damaging to the production
process. Items such as hand held tools, iron scrap, machinery tips, nails, wire, nuts and bolts are removed
from the process. Magnets are suspended over conveyor belts as the ore is moved from one place to
another.
The process of separating the desirable mineral from all the other minerals in the ore is known as ore
dressing. The type of separation technique used is dependent on the physical or chemical property of the
mineral. Some minerals are separated by density. This is called float – sink separation. The minerals are
crushed and then placed into a liquid. The materials that are less dense than the liquid will float and those
that are denser will sink.
Some minerals are separated because of their chemical properties. The mineral is crushed and then placed
into a solvent. The ore dissolves and then is poured off in solution which leaves the unwanted minerals
behind.
Some minerals are separated because of their particle size. These minerals are passed through sieves or
filters to separate the desired mineral from the unwanted.
Froth Flotation is another process used in the mining industry for separating the desired minerals from
the unwanted materials. Froth flotation takes advantage of whether or not minerals are attracted or
repelled by water.
http://www.theajmonline.com.au/mining_news/news/2010/january/january-14-10/featured-products/magnetic-separation-for-themining-industry
http://www.its-about-time.com/pdfs/mm56-65.pdf
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Year 7 Science Unit – Draft
Salt industry
ELABORATE
One method for the collection of salt involves separating the salt from the water.
This process is known as the salt evaporation process. It can really only occur in warm climates where the
evaporation rate is greater than the precipitation rate.
Salt water is captured in shallow ponds and the sun then goes to work evaporating away most of the water.
This leaves concentrations of salt behind.
http://www.mortonsalt.com/saltfacts/salt_prodproc.htm
Preparation
Organise 2 A3 pages with the name of an industry written across the top. You will need two pages for each
of the industries mentioned on the previous pages – 7 industries in total.
Have the different separation techniques on display for the students to see. – Resource Sheet 3
Lesson Outline
Key words: separation, filtration, sieving, evaporation, magnetism, visual separation, solvent, solute,
1. Place one group of the A3 pages at different locations around the room. Ask students to move around
the room recording what they think they already know about these industries on the sheet. Meet
together as a class and create a list of commonalities that are found within these industries. Highlight
the one important factor that the students will be investigating further – that all these industries use
separation techniques as part of their processing. Can students think of any other industries that
could be added to the list?
2. Distribute the remaining A3 pieces of paper around the room and then introduce the following
question to the class. How does the work we have been doing with mixtures, solutions and
separation techniques link to these industries? Give students some time to process and think about
this question and then give them some sticky notes to write on.
3. Ask students to move to one of the A3 sheets distributed around the room and to ensure that they
are roughly evenly spread. Once everyone is situated around a piece of paper ask the students to use
their sticky notes to record as much as they can about that particular industry and its use of
separation techniques. What do they already know and understand? What are the gaps? When they
have finished with one industry they could then move on to another giving them the opportunity to
record against all of the industries.
4. Meet together as a class and share some of the thinking. Students will then be asked to choose one of
these industries for further investigation.
Teacher Tip:
Students could randomly choose their industry based on their own area of interest or to ensure all
industries are covered they could choose an industry by taking a piece of paper with an industry
written on it from a bag.
You may like to have all of the class investigating the same industry
You may like to allow students to work alone or in pairs of their choice.
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Year 7 Science Unit – Draft
5. Give students a copy of Resource Sheet 15. Give them time to read through the information and then
allow time for questions and further clarification of the expectations. Work with the class to create a
list of presentation requirements. What are you expecting will be included? What is optional?
6. Provide time for students to complete the research and present their information to the rest of the
class or a wider audience.
Teacher Tip:
A rubric has been provided to help with the overall assessment of the key ideas and concepts of this
unit (Resource Sheet 18). This rubric does not get into the specifics of presentations, flow diagrams
and procedural texts. You may wish to develop your own rubrics to focus in on specific details for a
more detailed assessment of the literacy components.
Opportunities for extension
Students could engage in a debate relating to the development of a desalination plant. Students could be
presented with a statement such as “Desalinations plants - securing Adelaide’s water future”. They could
then research the pros and cons and then develop for and against arguments.
Students could write letters to the editor based around their research into current practice in areas such
as the significance of wetlands, desalination plants, recycling rubbish etc.
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Year 7 Science Unit – Draft
SEPARATION IN ACTION
Solutions, mixtures and separation
techniques are an important part of
our lives. Many industries use the
science and technology behind the
different separation techniques as part of their daily
processes.
You have been given an industry to investigate further. You will need to research
your industry and the separation techniques it uses. Once you have completed your
research you will need to organise a 2 minute oral presentation to present this
information to the rest of the class.
Questions to direct your research and thinking:
–
–
–
–
–
–
–
–
What is your industry?
What do they work with in terms of mixtures, solutions, pure substances compounds etc?
What separation techniques do they use?
How do these techniques help as part of the processes involved in the industry?
What issues are being resolved by the industry you have chosen?
Are there any negative impacts on society or the environment from the processes involved?
What is being done to overcome these?
What changes have happened over time within the industry with regards to the science and
technology involved?
You may wish to develop some resources to support your presentation e.g. a poster,
model, props, diagrams, photographs etc.
The key ideas you will need to consider when researching and organising this
presentation are..

Explaining how science and technology have contributed to finding solutions to
everyday problems

Giving examples of separation techniques used in people’s work and in industry

Explaining how these solutions may impact on other areas of society
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Resource Sheet 15
Year 7 Science Unit – Draft
Lesson 10: Demonstrating the Understanding
EVALUATE
At a Glance:
To provide opportunities for students to represent what they know about
solutions, mixtures and separation techniques and to reflect on the learning during the unit
Assessment Focus:
Summative Assessment of the conceptual learning outcomes is an important aspect of the Evaluate phase.
It involves monitoring students’ developing skills and understandings of the science concepts
Assessment Opportunities: Summative Assessment
 Participation in discussions
 Journal entries
 Presentation of understanding in an appropriate form
Science Outcomes:
Students will be able to:
 Engage in discussions around their knowledge and understandings of solutions, mixtures and separation
techniques
 Represent their understandings of science concepts in an appropriate format
Literacy Outcomes:
Students will be able to:
 Contribute to discussions
 Use written text to record their understandings and present this information to others
Lesson 10: Demonstrating the Understanding
Equipment for each student
 Individual science journals
 A copy of resource Sheet 17
 Access to unit photographs if needed
Teacher background information
Students will be asked to identify and represent as many links as possible between the key words that have
been used throughout the unit. What follows is an example of a way in which the words could be linked and
represented. This is not the only possibility and it is also not a completed example. It has been included to
give you a sense of the possibilities and the intended outcome from this lesson.
Teacher Tip:
Use Resource Sheet 16 as an example for the initial discussion only. Once students understand what is
expected and how they could demonstrate their understanding remove the example. This will encourage
students to develop their own representations rather than copy what someone else has produced.
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Year 7 Science Unit – Draft
REPRESENTATION OF UNDERSTANDINGS
Pure substance
Something which cannot be
separated into other parts
Mixtures
When two or more ingredients are mixed
together
Distilled water is a pure
substance.
Water is a common solvent
Solvent
A substance capable
of dissolving another
+
Soluble
Salt and sugar are soluble. This
means they dissolve in water
and create a solution.
Solute
A substance dissolved in
another substance
In a salt water solution the salt is the solute and
the water is the solvent
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Mixtures can be
separated
Solution
A mixture made up of one substance that
has dissolved into another
Decanting
When you separate a liquid from an
insoluble substance. Give the insoluble
substance time to settle and then pour the
liquid off the top
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Resource sheet 16
Year 7 Science Unit – Draft
Sieving
Separating a mixture of
different sized particles by
passing the mixture through a
sieve
Key words to consider
soluble
separation
insoluble
filtering
decanting
sieving
mixture
evaporation
pure substance
magnetic separation
saturated solution
visual separation
compound
solvent
suspension
solute
dilute
solution
concentrated
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Resource sheet 17
Year 7 Science Unit – Draft
Lesson Outline
Key words: separation, filtration, sieving, evaporation, magnetism, visual
separation, solvent, solute, solution, soluble, insoluble, decanting, mixture, pure
substance,
EVALUATE
1. Revisit the key questions for the unit with the class – “What are mixtures and solutions and why
might they need to be separated? What techniques can be used in the separation process?”
Give students a copy of Resource Sheet 17 and explain to them that those words are going to be the
focus of the lesson.
2. Ask students to find a partner and then get them to look at the words from the Resource Sheet
and choose two or more words that they think may be related to each other in some way. (See
resource Sheet 16 for examples) Ask them to explain the link between the words and then look for
other words that may link together.
3. Meet together as a class and share some of the thoughts. Ask the students to show how the words
mixtures and solutions can be linked together. Share some of these representations – using arrows
and boxes to show the relationships.
4. Students need to create a representation (poster, mind map, visual representation, concept map)
that demonstrate their level of understanding of the key words and the way these words link
together and are interrelated. (see Resource Sheet 16 for an example) Students may develop their
own way of representing the information. It is the content that is important. How well do they show
their level of understanding of the concepts involved?
5. Discuss with students what the key elements are. E.g. what is needed for the task to be completed
successfully? Provide students with an appropriate amount of time to complete the task.
6. Prepare a visual display of the different representations so the students can see what others have
produced.
7. Ask students to then record their responses to the following:
a) What are mixtures and solutions and why might they need to be separated?
b) What techniques can be used in the separation process? Give an example of each.
c) Explain how science and technology have contributed to finding solutions to everyday problems
with regards to chemistry and the separation of materials. Give examples.
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Year 7 Science Unit – Draft
Link to Learning
Mind Map and
Answers to
Questions
Separating the
Mess
Industry
Investigation /
Oral presentation
Answers to
Questions
Beginning
Achieving
Advanced
Science Understandings
Explains what is meant by pure
substances, mixtures and solutions
Attempts to explain the meanings but
lacks clarity and detail
Describes a variety of different
separation techniques and when and
where they may be used
Lists one or two separation techniques
and attempts to explain the science
behind them
Lists the different separation techniques
and explains the science behind them giving
some examples of their uses and using some
scientific terminology
Uses scientific terminology to clearly and concisely
explain the science behind the techniques and their
uses within the home or community
Science Inquiry Skills
Planning and Conducting
Plans and successfully conducts an
investigation working cleanly and
safely
Develops a basic plan for their
investigation including some details
around working safely
Develops a plan for their investigation which
includes all relevant details
Develops a well thought out, detailed plan for the
investigation including all relevant information
Works safely and responsibly and attempts
to maintain a clean work space and uses
equipment appropriately
Works safely, responsibly and with care and
accuracy
Evaluating
Suggests improvements to their
investigation methods
Provides basic responses to the
evaluation questions. More detail is
needed to provide a clearer
understanding
Suggests improvements to their investigative
process and gives appropriate reasons to
support their thinking
Gives detailed responses that clearly demonstrate
a reflective process. Suggests realistic ideas for
improvements and offers reasons for them
Communicating
Explains the separation process using
a flow chart
Has the basics needed for a flow chart
but lacks the detail needed to make it
clear and easy to follow
The flow chart contains relevant information
and makes good use of scientific terminology.
The information is sequenced and easy to
follow
Detailed, easy to follow flow chart which is well
labelled and clearly shows the links between the
processes involved. Uses scientific terminology
where appropriate
Explains the separation process using
a procedural text
A written procedure is attempted but is
not always clear and easy to follow. More
detail is needed.
Procedure makes sense and uses appropriate
conventions for procedural writing
Presents a detailed procedure which clearly follows
procedural writing conventions
Application – Science as a Human
Endeavour
Gives examples of separation
techniques used in people’s work and in
industry
Is able to give an example of a separation
technique that is used in people’s work
and industry
Is able to give several examples of
separation techniques that are used in
people’s lives and in industry
Is able to give numerous examples of where
separation techniques are used in people’s lives and
in industry
Explains how science and technology
have contributes to finding solutions
to problems
Attempts to describe a situation where
separation techniques have helped solve a
problem
Explains a situation where science has helped
solve a problem
Clearly explains the links between science and
problem solving by giving an in depth example of
where the science of separation has helped solve a
problem. Is able to look at the pros and cons of the
situation
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Clear explanations including some examples
and diagrams to support understanding
Clear, concise explanations supported by clearly
labelled diagrams
Can successfully give examples and use the words in
context
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Resource sheet 18
Year 7 Science Unit – Draft
Chemical Science
Equipment List

Measuring cylinders / beakers or plastic cups

Salt

Bicarb soda

Icing sugar

Citric acid

Sand

Sugar

Talcum powder

Small polystyrene balls

Iron filings

Marbles

Rice

Water

Materials to use for filtering – coffee filter paper, paper towel, chux cloths, muslin, etc

Materials for decanting – beakers, plastic cups, glass jars, measuring cylinders etc

Different sized sieves

Tweezers and chopsticks etc As well as a variety of materials that can be easily separated by
this technique e.g. buttons, different coloured beads etc

Variety of magnets – magnetic and non magnetic objects to be separated

Mixture containing – sand, iron filings, rice, salt and marbles

Polycarbonate vials
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Year 7 Science Unit – Draft