KS3 PHYSICS:
Matter
This is one of a series of documents designed to support science departments to integrate engaging and purposeful practical and investigative science activities within their current schemes of learning.
They highlight opportunities throughout the KS3 National Curriculum and identify possible purposes for each activity relating to the ‘Getting Practical’ project.
About this section of the curriculum
In this section of the curriculum, pupils should be taught about:
Physical changes
• conservation of material and of mass, and reversibility, in melting, freezing, evaporation, sublimation, condensation, dissolving
• similarities and differences, including density differences, between solids, liquids and gases
• Brownian motion in gases
• diffusion in liquids and gases driven by differences in concentration
• the difference between chemical and physical changes.
Particle model
• the differences in arrangements, in motion and in closeness of particles explaining changes of state, shape and density, the anomaly of ice-water transition
• atoms and molecules as particles.
Energy in matter
• changes with temperature in motion and spacing of particles
• internal energy stored in materials
Learning demand
Many physical changes will be familiar to pupils although they may have some misconceptions such as, ‘gases have no
mass’ and ‘when a liquid evaporates, it disappears’. The idea that all matter is made from particles is very abstract as
pupils cannot see the particles. This gives the topic a high learning demand. Using physical models such as marbles in
a tray and ball-park balls on a bedsheet really help pupils to understand the demanding scientific model. For further
information and support, see the Secondary National Strategy materials: ‘Strengthening teaching and learning of particles’
available from the National STEM Centre website:
http://www.nationalstemcentre.org.uk/elibrary/resource/5318/strengthening-teaching-and-learning-of-particles-key-stage-three-nationalstrategy-training-materials
See also the Secondary National Strategies study guide supporting particle theory:
http://www.nationalstemcentre.org.uk/elibrary/resource/5320/strengthening-teaching-and-learning-of-particle-theory-secondary-nationalstrategy
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Where this section of the curriculum fits in
This section of work covers some aspects of the following QCA topics:
7G Particle model of solids liquids and gases; 7H Solutions;
This section of work follows on from the KS2 curriculum where pupils are taught to:
• compare and group materials together, according to whether they are solids, liquids or gases (Y4)
• observe that some materials change state when they are heated or cooled, and measure or research the temperature at which this happens in degrees Celsius (°C) (Y4)
• identify the part played by evaporation and condensation in the water cycle and associate the rate of evaporation
with temperature (Y4)
• compare and group together everyday materials on the basis of their properties, including their hardness, solubility, transparency, conductivity (electrical and thermal), and response to magnets (Y5)
• know that some materials will dissolve in liquid to form a solution, and describe how to recover a substance from
a solution (Y5)
• use knowledge of solids, liquids and gases to decide how mixtures might be separated, including through filtering, sieving and evaporating (Y5)
• give reasons, based on evidence from comparative and fair tests, for the particular uses of everyday materials, including metals, wood and plastic (Y5)
• demonstrate that dissolving, mixing and changes of state are reversible changes (Y5)
• explain that some changes result in the formation of new materials, and that this kind of change is not usually reversible, including changes associated with burning and the action of acid on bicarbonate of soda (Y5)
Expectations
Within this section of the curriculum
in terms of working scientifically
all pupils will: investigate particle models and applications of the particle model such as diffusion and expansion; collect
and record observations and data; draw simple conclusions using experimental evidence such as what happens when a
solid is heated.
most pupils will: make predictions based on knowledge and understanding such as what will happen to the ring of
a ball and ring when heated; carry out investigations into diffusion and expansion with regard to safe working; interpret
observations they make during investigations such as why a ring of ammonium chloride forms close to one end of the
diffusion tube; identify further questions about particles and particle behaviour they might investigate.
some pupils will have progressed further and will: present reasoned arguments to explain investigation
outcomes and observations such as why some gases diffuse more quickly than others and why gases diffuse more quickly
than liquids; evaluate physical models to explain particle behaviour.
in terms of Physics: Matter
all pupils will: state that matter is made from particles; describe key similarities and differences between solids, liquids
and gases
most pupils will: state that matter is conserved in physical processes such melting, freezing, evaporation, sublimation,
condensation, dissolving and describe examples; describe the particle spacing and attraction of solids, liquids and gases;
recognise that physical changes are reversible; describe the differences between reversible and irreversible changes.
some pupils will have progressed further and will: explain Brownian motion in terms of particle collisions;
link ideas about energy and particles when explaining state changes, dissolving and diffusion.
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Health and safety
Risk assessments are required for any hazardous activity. In this section of the curriculum pupils:
• investigate the sublimation and desublimation of iodine
• use Bunsen burners for heating steel rods when investigating expansion
• investigate the diffusion of copper sulfate in water
Model risk assessments used by most employers for normal science activities can be found in the publications listed in
the Teacher’s guide. Teachers need to follow these as indicated in the guidance notes for the activities, and consider what
modifications are needed for individual classroom situations.
Language for learning
Through the activities in this unit pupils will be able to understand, use and spell correctly:
• words relating to matter, e.g. particle, solid, liquid, gas, melting, evaporating, boiling, condensing, freezing, dissolving, chemical, physical
• more specialised words relating to matter, e.g. diffusion, sublimation, Brownian motion, density, atom, molecule, expansion, bimetal strip, kinetic
• words with similar but distinct meanings, e.g. atom, molecule, particle; evaporating, boiling;
• words with different meanings in scientific and everyday contexts, e.g. boiling, freezing, model
• words and phrases relating to scientific enquiry, e.g. variable, data, table, graph, prediction, conclusion
Through the activities pupils could:
• write creatively about the journey of an iodine particle in an iodine crystal that warms up and sublimes, then diffuses in air and finally desublimes on a cold surface. This could be in the form of a comic strip.
Resources
Resources include:
Equipment Links:
• particle animations and particle models including a
kinetic model, ‘ball park’ balls on a bed sheet and
marbles in a tray and Molymod
ATOMIC STRUCTURE KIT
MARBLES
TRAYS
BIOCHEMISTRY SET
• iodine crystals, hard glass tubes and mineral wool
MINERAL WOOL
• ball and ring, bar and gauge, 50 cm steel bars,
bimetal strips
BALL AND RING
BAR AND GAUGE KIT
BIMETALLIC STRIPS KIT
• Whitley bay smoke cells and microscopes
WHITLEY BAY SMOKE CELL
MICROSCOPES
• diffusion tube, concentrated ammonia solution,
concentrated hydrochloric acid, pH paper strips
DIFFUSION CLOUD CHAMBER
CONCENTRATED AMMONIA AND HYDROCHLORIC
ACID
PH PAPER
• gas jars and lids, copper sulfate crystals
GAS JARS
GAS JAR COVERS
Independent Learning
Pupils could:
• visit libraries, museums or use the internet to find out more about the work of famous scientists such as Robert Brown,
Albert Einstein and their work with Brownian motion and kinetic theory
• use the internet to research the link between state changes and the water cycle
• read newspaper articles and watch television programmes relating to the topic
• carry out a project exploring the energy changes and particle spacing of water during the water cycle
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Getting Practical
The purpose of the practical work identified in this document relate to Getting Practical: Improving Practical Work in Science
http://www.gettingpractical.org.uk/
There is a detailed paper which supports the Getting Practical project written by Robin Millar entitled Analysing practical
activities to assess and improve effectiveness: The Practical Activity Analysis Inventory (PAAI)
A copy of this paper can be found at:
http://www.york.ac.uk/media/educationalstudies/documents/research/Analysing%20practical%20activities.pdf
Getting Practical learning objectives:
A: By doing this activity, pupils should develop their understanding of the natural world
A1: Pupils can recall an observable feature of an object, or material, or event
A2: Pupils can recall a ‘pattern’ in observations (e.g. a similarity, difference, trend, relationship)
A3: Pupils can demonstrate understanding of a scientific idea, or concept, or explanation, or model, or theory
B: By doing this activity, pupils should learn how to use a piece of laboratory equipment or follow a standard practical
procedure
B1: Pupils can use a piece of equipment, or follow a practical procedure, that they have not previously met
B2: Pupils are better at using a piece of equipment, or following a practical procedure, that they have previously met
C: By doing this activity, pupils should develop their understanding of the scientific approach to enquiry
C1: Pupils have a better general understanding of scientific enquiry
C2: Pupils have a better understanding of some specific aspects of scientific enquiry
Possible practical activities
Possible practical activities
Purpose
Equipment Links
Particle Model
Evaluating particle models
There are several models which are commonly used to demonstrate the particle
arrangement and movement of the three states of matter. These are marbles in a tray, ‘ball
park’ balls on a bed sheet, pupil role play and a purpose made kinetic model.
Once pupils experience the different models, they can start to evaluate strengths and weakness
in them For example, particles are not coloured like marbles and ball park balls etc.
Kinetic Theory Model
A2
A3
HE 18755
Kinetic Theory Projection Model
SI68190
This activity is good for pupils to develop explanations.
Atoms and molecules as particles
The particle models described in the previous activity are ‘good enough’ models to explain
state changes and the bulk properties of solids, liquids and gases. However, pupils need a
more sophisticated model as they encounter ideas about atoms and molecules. This idea
is very abstract to pupils and so getting pupils to build models using Molymod or other
suitable model is highly beneficial. Getting pupils to sort Molymod atoms and molecules is
a good way to teach ideas about elements, compound and mixtures.
x 10 Molymod Molecular Model:
A3
Introductory Set
MO 11301
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Possible practical activities
Possible practical activities
Purpose
Equipment Links
Physical Changes
Conservation of mass in state changes
Show pupils that the mass of 2-3 drops of water is about 0.10 g. You can demonstrate this
by using a large round bottomed flash with 2-3 drops of water in. Tightly stopper the flask
and measure the mass accurately (to 0.01 g). Gently warm the drops of water to evaporate
them and then reweigh the flask. The mass will remain the same unless there has been
loss of air past the stopper because of a pressure increase.
Nb. Some water will condense on the inside of the flask and appear as ‘mist’
A second investigation is into conservation of mass during dissolving, This is an
investigation which pupils can perform using salt and water. About 100 ml of water in a
beaker is weighed with a glass rod and a sample bottle containing about 10 g of common
salt. The salt is added to the water and dissolved by stirring and the equipment reweighed.
One common source of error is caused by pupils placing the glass rod on a bench after
stirring the salt solution. This transfers salt solution to the bench and so the equipment gets
lighter (contradicting the law of conservation of mass!)
Round Bottom Flasks
A1
A3
QFR50
Balance
BA110200
This investigation offers pupils an opportunity to analyse and evaluate data and
procedures.
Reversibility of state changes
Investigating the reversibility of most state changes is very low demand for most pupils. The
exception to this is sublimation. Pupils may carry out the investigation in a hard glass test
tube stoppered with mineral wool provided the amount of iodine is small (less than 0.25g
is suggested but a single crystal is enough). They should use a small purple flame (about 5
cm). The iodine crystal readily sublimes to form a purple vapour which desublimes as tiny
silver-grey crystals towards the top of the tube.
Iodine
A1
A3
IO3160
Mineral Wool
CE2016
This investigation provides an opportunity for pupils to describe and explain observations.
See CLEAPSS Hazcard 54A
Expansion
Bar and gauge: Show the pupils that the bar will fit in the gauge and the end of the bar
will fit in the circular hole. Heat the bar strongly and repeat. This demonstration supports
observation skills, explanation skills and drawing conclusions.
Ball and ring: Show the pupils that the ball slides through the ring when both are cold.
Now heat the ball strongly for a few minutes and then try it again. The ball will now sit on
the ring. Quenching the ball under the cold tap will quickly cause it to drop through the
ring. A second demo is to heat the ring and challenge pupil thinking about the outcome.
If the metal ring expands, will the hole in the middle become larger all smaller? This
demonstration supports critical thinking skills, explanation skills and drawing conclusions.
Ball and Ring
HE08895
Expansion of a metal rod
This can be performed as a class practical. One end of the steel rod is prevented
from moving whilst the other end is free to move on a bearing made from a needle. A
straw pushed onto the needle acts as a pointer to show the rotation of the needle. As
the steel rod is strongly heated, it expands and the straw rotates. Clamp stands are a
good source of steel rods and blocks of a suitable height will mean that the rods do not
need to be removed from their bases. This investigation offers pupils an opportunity to
make and record observations, write explanations and draw conclusions. http://www.
nuffieldfoundation.org/practical-physics/expansion-solid-rod
A1
A2
C2
Bar & Gauge Kit
HE08897
Bar Breaking Apparatus
HE18700
Bimetallic Compound Bar
HE08896
The bimetal strip
A bimetal strip bends as it is heated because of the differential expansion of the two metals
used to make them (often brass and steel). A good activity is to give the pupils the bimetal
strips for them to observe what happens when they are heated and allowed to cool. Set the
ground rule that they must not physically bend the rods by hand when cold or by pressing
it on a heatproof mat. A good challenge is for them to work out why the strip bends. This
activity supports critical thinking and explanation skills.
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Possible practical activities
Possible practical activities
Purpose
Brownian motion in gases
There is a variety of different equipment for pupils to see Brownian motion. A class
practical is an excellent way for pupils to see first-hand evidence of the existence of atoms
and molecules.
http://www.nuffieldfoundation.org/practical-physics/brownian-motion-smoke-cell
Equipment Links
Brownian Motion Apparatus
A1
A3
B1
C2
HE53652
A3
C2
Tubing, Soda Glass
Red Laser Pointer
OP11882
https://en.wikipedia.org/wiki/Brownian_motion
Diffusion in gases
There are several good demonstrations. These include the diffusion of nitrogen dioxide
in air (conducted in gas jars) - see CLEAPSS publication, L195 Safer chemicals, safer
reactions. A second demonstration uses perfume in a watch glass: the smell of the perfume
slowly spreads though the room. Make sure the windows and doors are shut for this one.
The ammonia and hydrogen chloride reaction is an excellent demonstration of diffusion.
It shows that gases diffuse in air and at different rates. Before setting up the experiment,
make sure that pupils know what to look for - show fumes of ammonium chloride by briefly
holding open bottles of concentrated HCL and ammonia next to each other. Make sure
the diffusion tube is level to avoid pupil claims that the different rate of diffusion is caused
by a ‘light’ gas rising or a ‘heavy’ gas falling. Add the hydrochloric acid ball first and the
ammonia ball second so that when the cloud forms near the hydrochloric acid end, it’s not
because the ammonia went in first. Finally, you can add more interest pupils by placing
strips of wet universal indicator paper on the inside of the jar at 10 cm intervals (a bit fiddly
but can be done with a log glass rod and a bit of patience). This activity supports critical
thinking, explanation skills and drawing conclusions.
TU16661
http://www.nuffieldfoundation.org/practical-physics/diffusion-ammonia-and-hydrogenchloride-gas
Diffusion in liquids
Drop about 10 g of copper sulfate crystals into a gas jar and place a lid on top. The
crystals will dissolve in an hour or so and the blue colour will slowly diffuse upwards over a
period of a few weeks. A key question to ask pupils is why diffusion in liquids takes much
longer that the diffusion in gases. This activity supports critical thinking, explanation skills
and drawing conclusions.
A1
A3
C2
http://www.nuffieldfoundation.org/practical-physics/diffusion-copper-sulfate-crystals-water
Energy and Matter
Changes with temperature in motion and spacing of particles
See Physics: Energy for activities about convection
Internal energy stored in materials
See Physics: Energy for investigations into cooling curves and state changes
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