Grade 6
Science
Unit: 04
Lesson: 01
Suggested Duration: 13 days
Elements, Compounds, and Evidence of Change
Lesson Synopsis:
In this unit, students will differentiate common compounds by name and symbol. Students should see examples
of reactions between substances that produce new substances very different from the reactants. They will
recognize that the formation of a new substance may be identified using the evidence of a possible chemical
change, such as production of a gas, change in temperature, production of a precipitate, or change in color. In
the previous lesson, students learned about elements. Students will be expected to recognize a few common
compounds and their chemical formulas. This is new material for Grade 6. In the previous set of TEKS, this
material was covered in Grade 7. Formulas and equations are studied in-depth in Grade 8.
TEKS:
6.5
6.5C
6.5D
Matter and energy. The student knows the difference between elements and compounds. The student is expected to:
Differentiate between elements and compounds on the most basic level.
Identify the formation of a new substance by using the evidence of a possible chemical change such as production
of a gas, change in temperature, production of a precipitate, or color change.
Scientific Process TEKS:
6.1
6.1A
6.1B
6.2
6.2A
6.2C
6.2D
6.2E
6.4
6.4A
Scientific investigation and reasoning. The student, for at least 40% of instructional time, conducts laboratory and
field investigations following safety procedures and environmentally appropriate and ethical practices. The student
is expected to:
Demonstrate safe practices during laboratory and field investigations as outlined in the Texas Safety Standards.
Practice appropriate use and conservation of resources, including disposal, reuse, or recycling of materials.
Scientific investigation and reasoning. The student uses scientific inquiry methods during laboratory and field
investigations. The student is expected to:
Plan and implement comparative and descriptive investigations by making observations, asking well-defined
questions, and using appropriate equipment and technology.
Collect and record data using the International System of Units (SI) and qualitative means such as labeled drawings,
writing, and graphic organizers.
Construct tables and graphs, using repeated trials and means, to organize data and identify patterns.
Analyze data to formulate reasonable explanations, communicate valid conclusions supported by the data, and
predict trends.
Scientific investigation and reasoning. The student knows how to use a variety of tools and safety equipment to
conduct science inquiry. The student is expected to:
Use appropriate tools to collect, record, and analyze information, including journals/notebooks, beakers, Petri
dishes, meter sticks, graduated cylinders, hot plates, test tubes, triple beam balances, microscopes, thermometers,
calculators, computers, timing devices, and other equipment as needed to teach the curriculum.
GETTING READY FOR INSTRUCTION
Performance Indicator(s):
• Create a tabbed or layered book. On each tab, include the formula of a compound, elements, and
number of atoms present in each compound.
On the back of the book, write a summary that explains the evidence for a chemical change taking place
as a new substance is formed. (6.2E; 6.5C, 6.5D)
5B, 5F, 5G
Key Understandings and Guiding Questions:
•
A compound is a substance made by chemically combining two or more elements.
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06/10/13
page 1 of 20
— Do compounds have different properties than the substances from which they are made?
•
The formation of a new substance may be identified by the evidence of a chemical change: production of
a gas, change in temperature, production of a precipitate, or color change.
— What are some common signs that a chemical change has taken place?
Vocabulary of Instruction:
•
•
compound
chemical formula
•
•
subscript
molecule
•
precipitate
Grade 6
Science
Unit: 04 Lesson: 01
Refer to Notes for Teacher section for materials.
Materials:
Attachments:
•
•
•
Handout: Building Blocks of Matter II (1 per pair)
Handout: Compounds and Elements (1 per student)
Teacher Resource: Compounds and Elements KEY
•Teacher Resource: Compounds and Elements Matching Cards (see Adv Prep, 1 set
per student, 4 sets per sheet)
• Handout: Water or Not (1 per group)
• Teacher Resource: Evidence of Chemical Reactions (see Adv Prep, 1 card per station)
• Handout: Elements, Compounds, and Evidence of Change (1 per student)
• Teacher Resource: Elements, Compounds, and Evidence of Change KEY
• Teacher Resource: Creating a Tabbed Book
Teacher Resource: Performance Indicator Instructions KEY (1 for projection)
Advance Preparation:
1. Prior to Day 1, consult the MSDS for all the chemicals used in the lesson for safety
precautions and safe disposal.
2. Prior to Day 1, prepare the Engagement activity. Pour a small amount of hydrogen
3.
4.
5.
6.
7.
8.
9.
peroxide in one beaker. Label this beaker “Y”. Pour an equal amount of water in another
beaker. Label this beaker “X”. Repeat this process for each group.
If you have not already had students attach a copy of the Periodic Table from the Grade 8
STAAR Reference Materials in their science notebooks, download and print copies of the
Periodic Table (STAAR Grade 8 Reference Materials (Periodic Table):
http://www.tea.state.tx.us/student.assessment/staar/ Click on “Science” under STAAR
Specific Resources, then “Grade 8 Reference Materials,” and go to page 2, 1 per
student). This is the chart that students will use on the Grade 8 STAAR test. Students
should be using this chart so they are familiar with it.
Print set of cards from the Teacher Resource: Compounds and Elements Matching
Cards. There are four sets of cards on the page. Each student will need one set of cards,
so cut apart the sets for easy distribution.
Prior to Day 5, prepare beakers of water and hydrogen peroxide for student designed
investigations. Prior to Day 6, thinly slice a raw potato so that a slice will fit in the beakers
used to hold the water and hydrogen peroxide. Cut each slice in half. Each group will
receive two halves of a potato slice. Note: The day the potatoes will be needed may vary,
so store potato slices in water to prevent oxidation.
Prior to Day 8, copy and laminate the Teacher Resource: Evidence of Chemical
Reactions Station Cards.
Prior to Day 8, prepare station materials per the Teacher Resource: Evidence of
Chemical Reactions.
Prior to Day 12, determine requirements and materials for the Performance Indicator.
Prepare attachment(s) as necessary.
Background Information:
In Grade 6, students will concentrate on developing an understanding of elements and compounds. It is important that
© 2008, TESCCC
06/21/11
page 3 of 20
Grade 6
Science
Unit: 04 Lesson: 01
students learn the differences between elements and compounds based on observations, description of physical
properties, and chemical reactions. Elements are represented by chemical symbols, while compounds are represented
chemical formulas.
In previous units, Grade 6 students were introduced to elements; compared the physical properties of metals, nonmeta
and metalloids, and the elements’ general placement on the periodic table according to physical properties.
In this unit, students differentiate between common elements and compounds by name and symbol. Students first learn
what a compound is and how it is represented in a chemical formula.
Students will then investigate examples of reactions between substances that produce new substances. They will learn
recognize that the formation of a new substance may be identified using the evidence of a possible chemical change,
such as production of a gas, change in temperature, production of a precipitate, or change in color. After this unit, these
concepts are not directly taught again in Grade 6.
STAAR Notes:
This is an important foundational piece for the understanding of elements, compounds, and their properties. In Grade 7
students will study physical and chemical changes as they relate to the digestive system. In Grade 8, students will stud
chemical formulas and equations, as well as chemical reactions as evidence of the formation of new substances with
different properties. 6.5C is identified as a Supporting Standard that will be tested on STAAR Grade 8 under Reporting
Category 1: Matter and Energy. Although 6.5D is not identified as a Supporting Standard, identifying the formation of a
new substance by using evidence of chemical change builds content for Supporting Standard 7.6B and Readiness
Standard 8.5E. Both Supporting Standard 7.6B and Readiness Standard 8.5E will be tested on STAAR Grade 8 under
Reporting Category 1: Matter and Energy.
GETTING READY FOR INSTRUCTION SUPPLEMENTAL PLANNING DOCUMENT
Instructors are encouraged to supplement and substitute resources, materials, and activities to differentiate instruction to
address the needs of learners. The Exemplar Lessons are one approach to teaching and reaching the Performance
Indicators and Specificity in the Instructional Focus Document for this unit. Instructors are encouraged to create
original lessons using the Content Creator in the Tools Tab located at the top of the page. All originally authored lessons
can be saved in the “My CSCOPE” Tab within the “My Content” area.
INSTRUCTIONAL PROCEDURES
Instructional Procedures
Notes for Teacher
ENGAGE – What a Difference an Atom Makes
NOTE: 1 Day = 50 minutes
Suggested Day 1
1. Divide the class into groups and review safety procedures for handling
unknown liquids.
2. Distribute a set of marked beakers to each group.
3. Instruct students to make some observations about the beakers in their
science notebooks. After students have written some observations ask each
group to share one observation.
4. Say:
• Even though the two substances look the same, they have very
different properties. The substance in beaker “X” is drinkable. The
substance in beaker “Y” is not drinkable, and in its pure form could
© 2008, TESCCC
06/21/11
Materials:
• safety goggles (1 per
student)
• beakers (small, labeled, s
Advance Preparation, 2 per
group)
•
water (per group)
•
•
hydrogen peroxid
(per group)
MSDS (hydrogen peroxid
page 4 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
be fatal if ingested. Both substances may be used to clean wounds
but one is more effective than the other.
5. Write the chemical formula for both beaker “X” (H2O) and for beaker “Y”
(H2O2) on the board. Under the formula draw the structure of the substances.
Do NOT write the names of the liquids yet.
Water molecule
6. Ask:
•
•
Hydrogen peroxide molecule
What do the circles represent? (Different elements)
Why are the circles different sizes? (They represent different
elements and each element has its own properties.)
•
In the previous lesson, we studied elements. What is the
definition of an element? (An element is a substance that cannot be
broken down chemically into simpler substances; the building block of
matter.)
•
Look at the formulas. How many elements are in each
formula? (Two elements in each formula, H and O.)
•
Using the information you just determined about the circles
for water, which circle do you think represents Hydrogen and how do
you know? (Hydrogen is represented by the smaller circles; the little
number in the formula tells you) You may need to explain that a subscript
is the little number written behind and below the element symbol to
represent the number of atoms in a formula.
•
What is the difference in the chemical formulas for water and
hydrogen peroxide? (An extra O or oxygen atom)
•
Since the two substances have very similar physical
properties, how could we tell which one is water and which one is
hydrogen peroxide? Answers may vary, so guide students toward the
idea of designing a way to test the properties of the substances.
1 per class)
Safety Notes:
Instruct students not to taste
contents of either beaker. Remind
them to be careful not to get any
liquid on themselves.
Review the MSDS for hydrogen
peroxide safety and disposal.
Instructional Note:
One of the sets of beakers will be
used in a later teacher
demonstration.
Science Notebooks:
Students record observations of
beakers in their notebooks.
7. Collect the beakers.
Say:
•
We will come back to these two substances later in the
lesson.
EXPLORE/EXPLAIN I – Building Blocks of Matter II
© 2008, TESCCC
06/21/11
Suggested Day 1 (continued)
page 5 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
1. Divide the class into pairs. Distribute approximately 12 plastic interlocking
blocks in three different colors to each pair of students.
2. Distribute a copy of the Handout: Building Blocks of Matter II to each pair.
3. Explain to the students that each block represents an element. Instruct the
students to select a colored block to represent each of the three elements.
Instruct the students to draw and color the blocks in the square that represent
each element.
4. Say:
• Each block represents a different element and it cannot be broken
•
5.
down into anything smaller. Elements are the building blocks of
matter.
Choose a block to represent Iron, Oxygen, and Sulfur, then draw and
color the blocks in the square that represents that element. Monitor
and assist students as necessary.
Project the definition of a compound on the board:
•
A compound is made from two or more elements that are
chemically combined and is not separated by physical means into
other substances.
6. Explain to students what a compound is:
Notes for Teacher
Materials:
• plastic interlocking blocks (3
different colors, 12 per pair)
• glue or tape (per group)
Attachments:
• Handout: Building Blocks o
Matter II (1 per pair)
Instructional Notes:
In Unit 3 students participated in a
activity called Building Blocks o
Matter. In Building Blocks of Matt
II, students will complete the activ
again, but with different elements
The activity is extended to assist
students in understanding the
difference between an element, a
compound, and a mixture. Guide
students through each definition a
then assist pairs as necessary.
Say:
•
A compound is made from two or more elements that are
chemically combined and is not separated by physical means into
other substances.
•
Create the compounds using your blocks and draw and color
your compounds in each square to represent Sulfate, Iron Oxide, and
Iron Sulfide. Hint: Use the small numbers to help you determine how
many blocks to use for each element. Monitor and assist students as
necessary.
Science Notebooks:
Students copy definitions and affi
handouts in their notebooks.
7. Instruct students to copy the definition of a compound in their science
notebooks. (You may wish to have students copy the definition on the back of
their handout.)
8. Project the definition of a mixture on the board:
•
A mixture is a combination or more than one substance, but it
does not create a new substance, and it can be separated.
9. Explain to the students what a mixture is:
Say:
•
A mixture is a combination of more than one substance, but it
does not create a new substance, and it can be separated. A salad is
© 2008, TESCCC
06/21/11
page 6 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
an example of a mixture, because you can remove parts of the salad,
such as tomatoes and onions from the salad.
•
Mixtures can occur with just elements, with compounds, or
with compounds and elements together.
•
Create the mixtures on your handout, with your blocks, and
then draw and color your mixtures in the squares. Monitor and assist
students as necessary.
10. Instruct students to copy the definition of a mixture in their science
notebooks. (You may wish to have students copy the definition on the back of
their handout.)
11. After students complete the table on the handout, construct a structure
with only one color of blocks and a structure that looks similar with two or more
colors of blocks.
12. Explain to the students that one structure is made of only iron blocks and
the other structure is made of multiple elements that are bonded together.
Ask:
• What is the difference between an element and a compound?
(Elements are made up of only one kind of “block” and compounds are
made up of different “blocks.”)
• What is the fewest number of blocks you could have to make a
compound? (Two)
• Look at the structure made of only iron blocks, why is this not
considered a compound? (It is made of a single element.)
• If I removed one block from the iron structure would it look similar to
the rest of the structure? (Yes, because it is a block of iron.)
• If I separated one block from the compound structure, would it be
similar to the larger structure? (No)
• Why not? Answers may vary. The block you removed is one element and
it does not have the other colors or elements in it, etc.
• What is the difference between a compound and a mixture?
(Compounds have elements bonded together and a mixture does not.)
13. Instruct students to affix the handout in their notebooks.
EXPLORE II – Compound Formulas
1. Divide the class into groups. Inform students they will be building models of
compounds and elements today.
2. Instruct one student from each group to gather five test tubes, a rack, and a
small amount of the materials to place in each test tube.
© 2008, TESCCC
06/21/11
Suggested Days 2 and 3
Materials:
• test tubes (5 per group)
• test tube rack (1 per grou
page 7 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
3. Once materials have been distributed, instruct another group member to blow
a small amount of air into a balloon and tie off the end.
4. Review the common name of the substances with the students. Ask students
to observe the substances and create a T-Chart in their notebooks labeled
Elements and Compounds. Then ask students to list each substance under
the correct column: elements or compounds. (Note: the substances are all
compounds, but do not tell the students at this time.)
5. Set the materials aside.
6. Distribute a set of the Teacher Resource: Compounds and Elements
Matching Cards to each student.
7. Instruct students to cut apart the chemical names and formulas on the
Matching Cards set.
8. Instruct students to match the chemical name of the compound cards to the
correct chemical formula cards. Demonstrate how to match “water” to “H 2O.”
9. Monitor students as they match the cards in their work area. Provide students
with “clues” that might assist them in matching the chemical name to the
formula.
10. Again, ask students to observe the substances. Ask students to review the
definition for a compound.
•
A compound is made from two or more elements that are
chemically combined and is not separated by physical means into
other substances.
11. Ask:
• After seeing the chemical formulas for each substance, do you need
to revise your T- Chart to correctly list any of the substances as
elements or compounds? How do you know? Accept appropriate
answers and acknowledge all the substances are compounds and made
up of elements.
12. Distribute the Handout: Compounds and Elements to each student.
13. Instruct students to glue the cards correctly on the Handout: Compounds and
Elements.
14. Instruct students to complete the handout by writing both the symbol and the
name of the elements found in each compound. Again, use water as an
example. ( H = hydrogen; O = oxygen)
© 2008, TESCCC
06/21/11
Notes for Teacher
• scoopulas (to dispense d
ingredients into test tubes, 2
teacher)
• pipettes (to dispense wet
ingredients into test tubes, 2
group)
• table salt (small amount p
group)
• chalk (1 piece per group)
• sand (small handful per
group)
• water (small amount per
group)
• honey (small amount per
group)
• balloon (1 per group)
• Periodic Table of the
Elements (see Advance
Preparation, 1 per student)
• scissors (1 per student)
• glue or tape (1 per studen
Attachments:
• Handout: Compounds an
Elements (1 per student)
• Teacher Resource:
Compounds and Elements
KEY
• Teacher Resource:
Compounds and Elements
Matching Cards (1 set per
student)
Instructional Notes:
These materials provide a concre
model to help students visualize t
abstract concept of compounds a
elements. Students are seeing a
science concept in concrete form
before working with the abstract
concept of symbols to represent t
same information.
Students may struggle with the
page 8 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
15. If students do not already have a copy of the Periodic Table of the Elements in
their notebooks, distribute a copy to each student (see Advance Preparation).
Instruct students to look for the substances on the Periodic Table of the
Elements.
16. Review the handout and make sure students have the correct elements listed.
17. Instruct the students to affix this chart into their science notebooks.
18. After the activity is complete:
Ask:
• Were any of the substances pure elements? (No)
•
•
•
•
•
•
•
•
•
•
•
How do you know? Answers may vary. None of the substances were
found on the periodic table; all of the substances were made of more than
one element, etc.
What was the most common element in all of the compounds?
(Oxygen)
Were any of the elements metals? (Yes)
Notes for Teacher
handout and matching cards.
Encourage students to use clues
the compound names to identify
elements they contain. Guide
students as necessary.
The compounds listed in this activ
are also listed in the specificity as
some that the students should
recognize.
Science Notebooks:
Students draw T–charts and affix
handouts in their notebooks.
How do you know? (Ca and Na were on the left side of the stair step on
the periodic table.)
Which element was a metalloid? (Silicon)
How do you know? (It is found along the stair step on the periodic table.)
Which compound had the most elements? (Fructose or honey)
If I poured honey on the sand, would that be a compound? (No, it
would be a mixture.)
Why not? (The elements would be mixed together but you could separate
them.)
If I take the oxygen out of water, will it still be water? (No, you need
hydrogen and oxygen to create water.)
What would it turn into? Answers may vary. If it were separated, it would
be hydrogen and oxygen would be left over.
19. Instruct groups to clean up materials for the next class, per your instructions.
EXPLAIN II – Compound Formulas
1. Ask:
•
When you were identifying the chemical formulas and
elements in the last activity, were you able to find the compounds on
the periodic chart? (No)
•
Why not? (Only elements are listed on the periodic table.)
•
Did the chemical names give you a clue as to some of the
elements that made up the compounds? (Some of names helped, but
© 2008, TESCCC
06/21/11
Suggested Day 4
Materials:
• beakers (1 with water and
with Hydrogen peroxide, from
the previous ENGAGE activit
per teacher)
page 9 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
some names didn’t include names of elements.)
2. Write Co and CO on the board and divide the class into pairs.
3. Ask:
What is the main difference between Co and CO? Answers may vary.
Co is the element Cobalt and is found on the periodic table; CO has two
elements, Carbon and Oxygen. CO is not on the periodic table.
4. Remind students that compounds are not found on the Periodic Table of
the Elements. Have them review the definition of a compound in their
notebooks and add this information:
•
A compound has different properties than the original
elements that formed it.
5. Refer students to the observations they made concerning the two beakers
of liquid used in the ENGAGE section. Display a pair of beakers filled with the
two substances.
•
plastic interlocking blocks
(from previous activity, severa
per teacher)
Instructional Notes:
The definition of a molecule for
Grade 6 will not include diatomic
elements. The concept of diatomi
molecules such as the atmospher
gases O2, H2, N2, and the halogen
gases will not be addressed.
Misconception:
• Students may think that
molecules have the same
properties as the atoms from
which they are composed.
6. Using the blocks from the Building Blocks of Matter activity, create a
structure that has two blocks of “hydrogen” and one block of “oxygen.” Explain
to the students what the blocks represent. Write the formula for water on the
board.
7. Say:
•
This chemical formula, H2O, is the formula for water. The
letters tell me there is an element in the substance.
•
When there is a little number written below the symbol, I
know there is more than one particle of that element. It is called an
atom.
•
In this formula, there are two blocks of hydrogen, or two
atoms of hydrogen.
•
There is only one block of oxygen, or one atom of oxygen.
Check for Understanding:
Ask for student volunteers to
summarize concepts using new
vocabulary.
Science Notebooks:
Students write definitions and
information in their notebooks.
•
Each element has its own atom and you will learn more about
atoms in 8th grade.
8. Project the following definition and instruct students to write it and the
following information in their notebooks:
•
A chemical formula is a combination of chemical symbols
showing the atoms of which a substance is made and their
proportions.
•
A chemical formula is like the ingredients to make a
compound. It tells you what elements to use and how much of each
element you need.
© 2008, TESCCC
06/21/11
page 10 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
9. Instruct students to write down H2O = 2 Hydrogen atoms and 1 oxygen
Notes for Teacher
atom as an example.
10. Instruct students to write H2O again and circle the two in the formula. Have
them label the two as subscript. Then write the following definition in their
notebooks.
•
A subscript is a number written just below the line that shows
how many atoms of an element are present in the formula.
11. Instruct students to draw the water structure made from blocks in their
notebooks and label the blocks as hydrogen and oxygen. Have the students
label the structure “water molecule.”
12. Instruct students to record the following definition in their science
notebooks:
•
A molecule is the smallest particle of a compound that can
exist on its own and keep its properties.
13. Remind students that molecules may have different properties than the
original elements. For example, CO2 is composed of the solid element carbon
and the oxygen gas and the molecule itself is a gas. (See instructional note on
diatomic molecules.)
14. Close the class by conducting a check for understanding.
15. Write Co2 on the board and ask the students to work with a partner to
answer the question.
Ask:
•
Is this an element or a compound? Why? (Co2 is an element
because there is only one element, Cobalt, in the formula. There are two
atoms of Cobalt.)
16. Give students time to discuss the answer to the question. Ask for
volunteers to share their thoughts.
17. Clarify misconceptions and say:
•
The subscript only changes how much of an element is
present in the formula, but it does not make an element into a
compound.
•
A compound has to have more than one element. CO2 is a
compound called Carbon Dioxide.
•
It has Carbon and also two atoms of Oxygen.
•
Look for more than one capital letter to identify a compound.
18. Write the names, chemical formulas, and diagrams of the structure of
© 2008, TESCCC
06/21/11
page 11 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
water and hydrogen peroxide on the board again (see the ENGAGE section).
19. Direct students’ attention to the two beakers. Allow students to share the
characteristics they observed earlier about the liquids.
20. Ask students to describe the similarities and differences in the formulas
using the terms atoms, elements, compounds, and subscripts.
EXPLORE III – Water or Not
Suggested Days 5, 6, and 7
1. Inform students that today they will be designing an investigation to determine
if the liquid in beakers from our earlier activity is water or not.
2. Remind students that scientists use several steps to solve problems and
document investigations.
3. Divide the class into groups.
4. Distribute a copy of the Handout: Water or Not to each group. Distribute to
each group two beakers with identical appearing liquids labeled “X” and “Y”
(see the preparation for the ENGAGE activity).
5. Say:
•
During this lesson, we have determined that both of these
liquids appear to be identical. Remember that one is water and one is
hydrogen peroxide.
•
Work with your partners to come up with a question to
identify the problem or question we are trying to solve. The students
should write something along the lines of “Which beaker contains
hydrogen peroxide and which beaker contains water?”
•
If you are familiar with peroxide, you will know that it will
bubble if placed on a cut. Water will not.
•
Record this information and any other observations you can
make about the two substances in part two of the Handout: Water or
Not. Students should record similar observations to those made during the
Engage activity.
•
In a few minutes you will work together to create a
hypothesis and design an experiment to test it. What is a
hypothesis? (It is a tentative explanation for an observation, or a
scientific problem that can be tested by investigation. It is not just an
educated guess.)
•
We can write a hypothesis in an “If, then” format.
•
Write the following on the board: “Ex. If I water the plant, then it
will grow.”
•
Every good experiment has an Independent Variable and a
Dependent Variable. Can anyone give the class a definition of the
© 2008, TESCCC
06/21/11
Materials:
• safety goggles (1 per student
•
•
•
•
•
beakers (small, 2 per group)
water (small amount per grou
hydrogen peroxide (small
amount per group)
raw potato slice (thin sliced, c
in half, see Advance Preparat
2 halves per group)
paper towels (several per gro
Attachments:
• Handout: Water or Not (1 pe
group)
Safety Notes:
Instruct students not to taste
contents of either beaker. Remind
them to be careful not to get any
liquid on themselves.
Review the MSDS for hydrogen
peroxide safety and disposal.
Instructional Notes:
The material for this activity must
prepared fresh and not held over
from the Engage activity. Hydroge
peroxide will deteriorate if left in li
for several days, so you will need
replace it for Days 6 and 7. Potato
slices may be stored in water to
prevent oxidation. Students will no
page 12 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
two? Answers may vary. An Independent variable is what the researcher
changes in an investigation and the dependent variable is what you
observe or measure to determine if there was an effect.
•
When writing a hypothesis the independent variable is written
first and the dependent variable is written second. In our example the
independent variable is the water for the plant. The dependent
variable is the growth of the plant, what we will measure to see if the
water had an effect.
•
Underline water and label it Independent variable, then double
underline grow and label it dependent variable.
6. Remind students:
•
It is not proper lab procedure to experiment on your body.
You may not taste or place the liquids on your skin.
•
You may not experiment on any person.
•
I will give you a piece of potato. You have five minutes to try
to figure out a way to tell these liquids apart.
•
Do not test any materials yet, only brainstorm an idea for an
experiment.
be ready to conduct their tests un
Day 6. This may vary based upon
the readiness level of your studen
Grade 6 TEKS 6.2A require stude
to plan and implement comparativ
and descriptive investigations by
making observations, asking welldefined questions, and using
appropriate equipment and
technology.
Science Notebooks:
Students are to draw the activity s
up and write procedures and
observations in their notebooks.
Additionally, students affix the
handout in their notebooks.
7. Give students five minutes to brainstorm for ideas to test the liquids. Allow
each group to share their idea for an experiment with the class. Acknowledge
all ideas.
8. Assist the class in identifying the independent variable (liquids) and the
dependent variable (bubbles).
9. Ask the students to write their hypotheses on the Handout: Water or Not and
then share with the class. An example would be, “If I pour hydrogen peroxide
on the potato, then it will make bubbles,” or “If I pour water on the potato, then
it will not produce bubbles.”
10. Instruct students to draw the setup for their investigation, and also to write the
procedures to test the experiment on step 4 of the Handout: Water or Not.
11. Remind them they are still not ready to test.
12. Assist the students in creating a data table to record their results.
Ask:
•
What is going to tell you if you have water or peroxide? (A
lack of bubbles for water and bubbles for Hydrogen peroxide)
•
Create a data table to keep track of our results. Will one trial
be enough? (No, there should be multiple trials.)
13. Guide students to create a table such as the one below. In this example,
students would indicate if bubbles were present for each trial with a yes or no.
© 2008, TESCCC
06/21/11
page 13 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Substances
Water
Hydrogen
Peroxide
Trial1 Bubbles
Trial 2 Bubbles
Notes for Teacher
Trial 3 Bubbles
14. Instruct the
students to
begin their
experiment
and remind them to record the data as they go through each trial.
15. Ask students to draw a conclusion about the results of their experiment.
Say:
•
Look at your results and draw a conclusion about hydrogen
peroxide and water. Make sure that you say whether or not your
hypothesis was correct.
•
Explain why or why not.
•
Do not change your hypothesis. If your hypothesis is not
correct, it does not mean that your experiment is not helpful.
•
Having an incorrect hypothesis is just as important and
having a correct one.
16. Ask students to finish their handouts and to make sure they used complete
sentences to make their experiment clear to others.
17. Ask the students to share their findings with the class.
18. Instruct groups to clean up their materials and return all items per your
instructions.
EXPLAIN III – How it Works
1. Facilitate a discussion:
•
During our investigations, you learned that hydrogen
peroxide is used as an antiseptic to wash cuts. One characteristic of
hydrogen peroxide is that it will produce bubbles when applied to a
wound. Water will not. The formation of bubbles is one sign that a
chemical reaction has taken place.:
•
Does anyone know how hydrogen peroxide makes the
bubbles? Accept all answers. A more detailed explanation of what
occurred is included below.
•
Hydrogen peroxide is 3% H2O2 and 97% water.
•
•
Suggested Day 7 (continued)
Instructional Notes:
A detailed explanation is provided
but may be more than Grade 6
students need at this point.
Students are not to be held
responsible for the explanation of
how hydrogen peroxide works, bu
the explanation is provided to sati
the “why” questions students may
ask.
Blood and cells contain an enzyme called catalase.
A cut or scrape contains both blood and damaged cells
releasing catalase.
•
When hydrogen peroxide comes into contact with the
catalase, a chemical reaction occurs.
•
The reaction of the catalase and hydrogen peroxide causes
© 2008, TESCCC
06/21/11
page 14 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
the peroxide to turn to water and release the extra oxygen as a gas.
•
The bubbles are pure oxygen gas being created by the
reaction.
•
Potato cells are damaged when cut. They release catalase as
well. This is why bubbles appear on the potato slice in the peroxide
beaker and not the water beaker.
EXPLORE IV – Chemical Reactions
1. Explain to students they will be participating in a station activity over the
next two days to investigate chemical reactions.
2. Say:
•
Remember that compounds are two or more elements
combined chemically to create a new substance. Today we are going
to investigate to determine what evidence we can find to indicate a
chemical change has occurred.
3. Set up lab stations prior to class. Stations can be set up all at once and
groups will rotate though the stations over two days.
4. Divide the class into groups and review station procedures with the
students. This review should include safety concerns as well as station clean
up issues.
5. Instruct students to sketch and label the activities in their notebooks.
Additionally, students will summarize the procedures for each station and
record detailed observations during each activity.
6. Monitor and assist groups as they move through each station. Use a
signal to facilitate group movements between stations.
© 2008, TESCCC
06/21/11
Suggested Days 8 and 9
Materials:
• triple beam balance (1 pe
Station A)
• resealable plastic bag
(freezer weight, pint sized, 1 p
group at Station A)
• calcium chloride (5 g per
group at Station A)
• water (25 mL per group a
Station A)
• thermometer (with backin
1 per Station A)
• graduated cylinder (1 per
Station A)
• timer (1 per Station A)
• safety goggles (1 per
student, per Station B)
• triple beam balance (1 pe
Station B)
• cup (foam, 1 per Station B
• baking soda (15 g, per
group, per Station B)
• vinegar (25 mL per group
per Station B)
• thermometer (with backin
1 per Station B)
• graduated cylinder (1 per
Station B)
• timer (1 per Station B)
• spoon (plastic, 1 per Stat
B)
• triple beam balance (1 pe
Station C)
• baking soda (2g, per grou
per Station C)
page 15 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
•
calcium chloride (2g, per
group, per Station C)
• beaker (100 mL, 1 per
Station C)
• water (40 mL, per group,
Station C)
• cups (clear plastic, 2 per
Station C)
• spoon (plastic, 1 per Stat
C)
• safety goggles (1 per
student, per Station D)
•
apron (1 per student, per
Station D)
•
jars (baby food size, 2 pe
Station D)
•
•
water (per Station D)
food coloring (red, 1 bottl
per Station D)
• spoon (plastic, 1 per Stat
D)
• liquid bleach (a few drops
per group per Station D)
•
pipette or eyedropper (1 p
Station D)
•
safety goggles (1 per
student per Station E)
•
balloon (1 per group, per
Station E)
•
funnel (plastic or paper, 1
per Station E)
•
baking powder (15 mL pe
group, per Station E)
•
•
vinegar (per Station E)
plastic water bottle (1,500
mL, empty, 1 per Station E)
Attachments:
• Teacher Resource: Evidence
© 2008, TESCCC
06/21/11
page 16 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
Chemical Reactions (see
Advance Preparation, 1 card
station)
Instructional Notes:
Set up lab stations prior to class.
Stations can be set up all at once
and groups will rotate though the
days.
EXPLAIN IV – Evidence of Chemical Change
1. Facilitate a discussion of the results from the previous day’s investigation.
Ask students to report observations and changes in temperatures recorded.
Write student observations on the board as students report them. Use the
results to guide students to the conclusion that there were chemical reactions,
and that those reactions produced evidence of chemical change.
2. Ask:
• What happens when we mix two substances and a new substance is
created? Answers may vary. A compound is formed/a chemical change
has occurred.
3. Say/Ask:
• During a chemical reaction, the bonds between atoms in a substance
•
•
•
•
•
are broken. The atoms rearrange themselves and form bonds with
new substance partners.
There are different types of bonds and they hold atoms together. You
will learn about the processes of bonding in high school science
courses.
What types of evidence did we see in our investigation? Answers will
vary, but should include production of a gas (odor, bubbles), change in
temperature, production of a precipitate, and change in color.
Based on the previous investigation, what is a good definition of a
chemical change? Answers may vary. A chemical change is when two
substances come together and create something new; the new substance
cannot be separated into the old substances.
Chemical reactions involve a change in chemical makeup in the
substances which we were investigating. You cannot easily get back
your original substances because something new has been formed.
Have you ever tried to take a fried egg and turn it back to its original
state? The properties of the original substances are different than
the properties of the new substances that are formed.
4. Instruct students to work with a partner to create a definition of a chemical
change in their notebooks. Allow a few minutes for discussion and then ask for
© 2008, TESCCC
06/21/11
Suggested Day 10
Materials:
• Periodic Table of the Element
(see Advance Preparation, 1
student, previously distributed
Attachments:
• Handout: Elements,
Compounds, and Evidence
Change (1 per student)
• Teacher Resource: Elements
Compounds, and Evidence
Change KEY
Instructional Notes:
Iron (Station A) is an element. The
compound space should remain
blank.
The Evidence of Change box is fo
the documentation of the type of
change that occurred when all the
substances were mixed together.
Misconception:
• Students may think molecules
have the same properties as
atoms from which they are
composed.
Science Notebooks:
page 17 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
volunteers to share with the class.
5. Work with the class to formulate an appropriate definition for a chemical
change. Encourage students to revise their definitions as appropriate.
Students list the four signs of a
chemical reaction and a brief
description of each in their notebo
Additionally, students affix their
handouts in their notebooks.
6. Ask:
• How could we identify a chemical change? Accept all answers at this
time; color change, temperature change, odor change, a precipitate is
formed, or a gas is formed.
7. Say:
• There are several ways to tell if substances have undergone a
•
•
•
chemical change when they are mixed together.
Some evidences are:
o a change in odor/ production of a gas
o a substance disappears
o a change in form
o light or sound is given off
This list is not complete. Sometimes a chemical change can look like
a physical change. For example, two changes in form can be
compared. If you tear paper it is a physical change, but if you burn
paper, it is a chemical change.
During a chemical change new substances are being created, where
do you think the matter for the new substance comes from? Answers
may vary. The new substances are created by rearranging the elements
from the old substances.
8. You will have to know four indicators that are evidence that a
chemical change has taken place. Write these in your notebooks.
• Production of a gas– Bubbles form or an odor forms upon mixing
substances together.
• Change in temperature– It takes energy to break chemical bonds.
When the reaction involves more bond breaking than bond making,
the energy needed is absorbed from the surroundings. This makes
the temperature cooler. If there is more bond making than bond
breaking, extra energy is released. This makes the temperature
increase.
• Production of a solid precipitate– When mixing a pair of substances
that dissolve in liquid, the sudden appearance of a solid that “rains
down” (precipitates) into the bottom of the container is a sign that a
reaction has occurred. Sometimes the particles are too small to
settle to the bottom and just make the solution look cloudy.
• Change in color– Every compound absorbs a characteristic set of
colors of light. This color is like a fingerprint for that compound. If
the compound changes, the color can change.
© 2008, TESCCC
06/21/11
page 18 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
9. Distribute the Handout: Elements, Compounds, and Evidence of
Change to each student.
10. Instruct students to use their periodic tables and their notes from the
stations activities to fill in the table.
11. Instruct students to write the symbols for the elements in each substance,
the chemical formula for the compound, the type of chemical change, and an
explanation of what evidence there was for the change.
12. Monitor and assist as necessary. Students should affix the handout in their
notebooks.
ELABORATE – Diagraming Change
Suggested Day 11
1.
•
•
•
•
Orally or in writing, give the following instructions to students:
Fold an index card vertically and then horizontally into fourths.
Unfold the card and draw an oval in the center where the folds intersect.
In the oval, write “Evidence of Chemical Change”.
Draw lines on the folds to the point where they meet the oval.
•
Write one of the following labels near the top of each quadrant: color
change, temperature change, a solid precipitate forms, or gas bubbles
form.
Draw a representation of each indicator of a chemical change in each
quadrant.
Affix the note cards to your notebooks.
•
•
2. Instruct the students to write a paragraph in their notebooks, using the
index cards they just made. The topic of the paragraph will be how they know
a chemical change has occurred. Additionally, students should give an
example of each type of evidence using the following sentence stem:
• A chemical change has occurred when I mix _____________________. I
can identify a chemical change if I observe…
EVALUATE – Performance Indicator
Instructional Note:
Graphic organizers, such as with
Frayer Model style graphic, assist
students in visualizing key concep
Suggested Days 12 and 13
Performance Indicator
• Create a tabbed or layered book. On each tab, include the formula of a
compound, elements, and number of atoms present in each compound.
On the back of the book, write a summary that explains the evidence for a
chemical change taking place as a new substance is formed. (6.2E; 6.5C,
6.5D)
5B, 5F, 5G
1. Refer to the Teacher Resource: Performance Indicator Instructions
© 2008, TESCCC
Materials:
• index cards (large, 1 per
student)
• markers or colored pencil
(per group)
• glue or tape (per group)
06/21/11
Materials:
• paper (see Advance
Preparation, 5 half sheets per
student)
• scissors (per student)
•
staples, tape, or glue (per
page 19 of 20
Grade 6
Science
Unit: 04 Lesson: 01
Instructional Procedures
Notes for Teacher
KEY for information on administering the assessment.
group)
Attachments:
• Teacher Resource: Creating
Tabbed Book
• Teacher Resource:
Performance Indicator
Instructions KEY (1 for
projection)
© 2008, TESCCC
06/21/11
page 20 of 20