Additional guidance
T
Handout 2.18 is not included in participants’ packs in order to prevent the activity
in this task being pre-empted. You will need to have ready sufficient photocopies
for each participant.
Using role-play to demonstrate ideas
of particle theory and address common
misconceptions
15 minutes
Task D
Show slide 2.8 to introduce task D.
Slide 2.8
Task D
Using role-play to demonstrate ideas of particle
theory and address common misconceptions
Slide 2.8
• Pupils have misconceptions about changes in materials.
• Several of these misconceptions are quite common.
• Use role-play to model particles.
• Retrieve handouts 2.9 and 2.10.
Say that:
Handouts 2.9 & 2.10
32
•
There are a number of misconceptions that pupils may have about material
change. Participants should briefly be reminded of the misconceptions identified
from the pre-unit task in task B.
•
Research suggests that several of these misconceptions are quite common.
•
We are going to do a role-play exercise where participants behave in a manner
analogous to particles, to address some of these misconceptions.
Ask participants to retrieve handouts 2.9 and 2.10, which describe the method of
role-play and some phenomena and misconceptions. Quickly run through the
instructions on the first page of the handout. If participants have done this sort of
role-play before, suggest that they model some of the phenomena for the gifted
and talented on handout 2.17. Ask participants to work in groups of six. There are
about 10 minutes available for this part of the task.
| Strengthening teaching and learning of particles in Key Stage 3 science | Session 2
| Notes for tutors
© Crown copyright 2003
Handout 2.9
Handout 2.10
Task D Using appropriate
teaching and models to
address misconceptions
Task D Instructions for using
role-play to demonstrate particle
theory
1
Each participant represents a single particle of a substance, e.g. a molecule of
water.
2
Each participant should vibrate (shake) and this will become more vigorous as
kinetic energy and therefore temperature increases.
3
Participants should be:
4
–
close together and in a pattern for a solid;
–
moving about but still frequently in contact for a liquid;
–
able to move freely and quickly anywhere, but in a defined space, for a gas.
1 of 2
Here is a list of some frequent misconceptions about particles held by pupils at the
start of Key Stage 3.
1
Role-play as in the diagrams below.
When a solid dissolves in water it is no longer there; its substance has
disappeared.
2
Dissolving and melting are the same thing.
3
An insulated cold substance is heated up by the insulating material, e.g. a
snowman is warmed by having a coat put on.
4
The condensed water on the outside of a glass beaker containing iced liquid
water comes from the iced water and not from water gas in the atmosphere.
5
There needs to be a high temperature for evaporation to occur.
6
Gases have no weight.
7
The bubbles in boiling water mainly contain air (rather than gaseous water).
8
Many pupils confuse the irreversible changes (burning) with the reversible
changes (e.g. melting) that occur in a burning candle.
9
Many will not have an understanding of how a solid changes to a liquid which in
turn can then change to a gas.
Select one of these misconceptions to work on. Decide how you would plan to
overcome it in your teaching. Explain the teaching sequence, the practical work
and/or the model(s) you might use.
Treatment of the third misconception above is illustrated on page 2 of this handout.
The sequence assumes that pupils have met the particle model and have been
through the role-play exercise. Pupils are also assumed to have experience of using
computer data-logging apparatus.
43
5
Particles in solids are closely packed, held by strong forces. They cannot move
from a fixed point, except to vibrate, and have very small spaces between
them.
6
Particles in a liquid are loosely packed in a random arrangement with very small
spaces between them. The forces between particles in a liquid are weaker than
in solids and the particles can move around each other.
7
Particles in a gas have, on average, larger spaces between them than in liquids
or solids. The particles in a gas move in straight lines, and the forces between
the particles are very weak except when they collide.
| Strengthening teaching and learning of particles in Key Stage 3 science | Session 2
| Notes for tutors
© Crown copyright 2003
44
| Strengthening teaching and learning about particles in Key Stage 3 | Session 2
| Notes for tutors
© Crown copyright 2003
Circulate around the groups as they work. Use this time both to offer support and
to look for any particular suggestions to pick out in a brief report back from groups.
Additional guidance
T
The standards report on Key Stage 2 science published by QCA and available on
their website describes the science topics where misconceptions commonly occur.
You may wish to nominate a particular phenomenon for each group to ensure that
all are tackled.
There should be a minimum of six participants to model the phenomena effectively.
If there is a small number of participants, they can still model the nature of particles
in solid, liquid or gaseous state and the changes from one state to another, but
perhaps model the other phenomena on paper.
Slide 2.11
Say that Year 7 pupils should be encouraged to apply the particle model to explain
events and phenomena they encounter. Show slide 2.11 and ask participants what
would be the features of the role-play that would help explain the phenomena. This
is for discussion only.
(The slide is reprinted as handout 2.11.)
Handout 2.11
Slide 2.11
Examples of phenomena taught in the Year 7 yearly
teaching objectives
• Solids and liquids are much less compressible than gases
• Heating causes expansion in solids, liquids and gases
• Air exerts a pressure
• Why there are changes of state
• Why mass is conserved when substances dissolve to form solutions
• Why saturated solutions form
• Why temperature increases are likely to result in substances dissolving more
quickly
33
| Strengthening teaching and learning of particles in Key Stage 3 science | Session 2
| Notes for tutors
© Crown copyright 2003
Ask participants to think about how they could explain that solid and liquid
substances become more soluble with increasing temperature but gases become
less soluble. Tell them that you will ask them to use their ideas in the plenary. Make
it clear that this is not part of the Key Stage 3 programme of study and it is
intended for the participants to apply their growing understanding of the particle
model, not to be taught to pupils.
Using particle theory to explain
practical demonstrations
25 minutes
Task E
18 minutes
Ask participants to watch the three practical demonstrations and then discuss in
pairs their explanations for what has happened in one of them, in terms of particles.
Get them to produce an annotated diagram on a poster or OHT to explain the
phenomena. Participants should briefly put one or two suggested strengths of their
model on sticky labels and then put them in the appropriate box on handout 2.12.
They should then comment on one or two limitations of their model in the boxes of
the bottom row.
Handout 2.12
Handout 2.12
Task E Using particle theory to explain practical
demonstrations
1 of 2
47
Chromatography of felt pen ink
SUGGESTED
STRENGTHS
Egg in a bottle
© Crown copyright 2002
S UGGESTED
LIMITATIONS
| Strengthening teaching and learning about particles in Key Stage 3 | Session 2
| Notes for tutors
Collapsing plastic bottle
Handout 2.19 (not in participants’ packs) gives some possible responses.
Handout 2.19
Handout 2.19
Task C Analysis of possible models for the three
demonstrations
© Crown copyright 2003
SUGGESTED
STRENGTHS
S UGGESTED
LIMITATIONS
| Strengthening teaching and learning about particles in Key Stage 3 | Session 2
| Notes for tutors
DESCRIPTION OF MODEL
52
34
Collapsing plastic bottle
Egg in a bottle
Chromatography of felt pen ink
Heating the air increases the kinetic energy of
the air particles. These hit the inside of the
bottle with a resultant pressure equal to that
outside. Cooling reduces the kinetic energy of
the particles in the closed bottle and there are
less frequent collisions. Therefore the pressure
inside is lowered. The outside pressure is now
relatively greater because of more particle
collisions with the outside, so the walls
collapse.
The hot air inside the bottle consists of air
particles with high kinetic energy. As the air
particles transfer energy to the bottle walls
their kinetic energy reduces. The collisions
of air particles on the bottom of the egg
are less frequent than those on the top, so
the egg is pushed into the bottle.
The particles of solvent give piggy back
rides to the solute particles. The lighter,
smaller solute particles rise more quickly
than larger solute particles.
Explains why the bottle is not initially crushed
by external air pressure.
Identifies particle collisions as the cause of
pressure.
Suggests a mechanism for the movement
of solute particles.
Links temperature and kinetic energy of the
particles.
Links temperature and kinetic energy of the
particles.
Explains why some colours travel further
than others.
No mention of energy transfer.
Doesn’t explain why the egg can change
shape, move into the bottle and not break.
Doesn’t explain why solvent moves through
the paper.
The position of collapse is not predicted.
Doesn’t explain why solvent particles can
rise up vertical filter paper against the force
of gravity.
| Strengthening teaching and learning of particles in Key Stage 3 science | Session 2
| Notes for tutors
© Crown copyright 2003
Handout 2.9
Task D Instructions for using
role-play to demonstrate particle
theory
43
1
Each participant represents a single particle of a substance, e.g. a molecule of
water.
2
Each participant should vibrate (shake) and this will become more vigorous as
kinetic energy and therefore temperature increases.
3
Participants should be:
–
close together and in a pattern for a solid;
–
moving about but still frequently in contact for a liquid;
–
able to move freely and quickly anywhere, but in a defined space, for a gas.
4
Role-play as in the diagrams below.
5
Particles in solids are closely packed, held by strong forces. They cannot move
from a fixed point, except to vibrate, and have very small spaces between
them.
6
Particles in a liquid are loosely packed in a random arrangement with very small
spaces between them. The forces between particles in a liquid are weaker than
in solids and the particles can move around each other.
7
Particles in a gas have, on average, larger spaces between them than in liquids
or solids. The particles in a gas move in straight lines, and the forces between
the particles are very weak except when they collide.
| Strengthening teaching and learning of particles in Key Stage 3 science | Session 2
| Notes for tutors
© Crown copyright 2003
Handout 2.10
Task D Using appropriate
teaching and models to
address misconceptions
1 of 2
Here is a list of some frequent misconceptions about particles held by pupils at the
start of Key Stage 3.
1
When a solid dissolves in water it is no longer there; its substance has
disappeared.
2
Dissolving and melting are the same thing.
3
An insulated cold substance is heated up by the insulating material, e.g. a
snowman is warmed by having a coat put on.
4
The condensed water on the outside of a glass beaker containing iced liquid
water comes from the iced water and not from water gas in the atmosphere.
5
There needs to be a high temperature for evaporation to occur.
6
Gases have no weight.
7
The bubbles in boiling water mainly contain air (rather than gaseous water).
8
Many pupils confuse the irreversible changes (burning) with the reversible
changes (e.g. melting) that occur in a burning candle.
9
Many will not have an understanding of how a solid changes to a liquid which
in turn can then change to a gas.
Select one of these misconceptions to work on. Decide how you would plan to
overcome it in your teaching. Explain the teaching sequence, the practical work
and/or the model(s) you might use.
Treatment of the third misconception above is illustrated on page 2 of this handout.
The sequence assumes that pupils have met the particle model and have been
through the role-play exercise. Pupils are also assumed to have experience of using
computer data-logging apparatus.
44
| Strengthening teaching and learning of particles in Key Stage 3 science | Session 2
| Notes for tutors
© Crown copyright 2003
Handout 2.10
2 of 2
Misconception 3: An insulated cold substance is heated up by the insulating
material, e.g. a snowman is warmed by having a coat put on.
Objective: To demonstrate that thermal insulators slow down the rate at which
energy is transferred from an object with a higher temperature to one with a lower
temperature.
Starters
20 minutes in total (10 + 10)
The teacher asks pupils to define thermal insulator. Pupils suggest that an insulator
slows down the rate that ‘heat’ travels. The teacher then asks pupils where would
they meet thermal insulators in their everyday life. Pupils suggest a jumper, tea cosy
or astronaut’s suit, etc.
The teacher then gets pupils to work in pairs and discuss their ideas, with their
reasoning, using particle theory, for the concept cartoon 8.2 ‘The snowman’. After
5 minutes discussion the pupils debate their ideas in groups of four. This is fed
back, after 4 minutes, via one spokesperson to the rest of the class.
Main sequence
25 minutes
The teacher asks the pupils to consider the definition of a thermal insulator given in
the objective. The teacher asks them to design a role-play sequence where they
represent the particles of snow covered by the coat material. Pupils are asked to
suggest the factors that would change any features of their role-play.
One group of pupils is asked to carry out their role-play and the other groups are
asked to list the strengths and limitations of the model that they observe.
Plenary
10 minutes
The teacher discusses the strengths and limitations of the role-play with pupils.
Pupils in groups of four are then given a loop card activity with eight cards with
questions and answers. (Examples are: ‘A tea cosy placed over a pot of hot tea
will…’ The answer will be on another card ‘…slow cooling of the liquid.’ ‘A tea cosy
placed over a jug of iced tea will…’ The answer will be ‘…slow down the melting of
the solid.’) The pupils will be competing to find out which group completes the loop
quickest.
Homework setting
5 minutes
The teacher then gives out graph paper with horizontal and vertical axes. The
horizontal is labelled ‘time in minutes’ and the vertical ‘temperature in degrees
Celsius’. The teacher tells the pupils that in the next lesson they are going to use
computer data-logging with two temperature sensors to investigate thermal
insulation. The sensors will be placed in icy water in two separate containers. One
container will be completely surrounded by a woolly envelope. The pupils’ task is to
suggest what the shape of the lines of the graph will be as time passes and to
describe what will happen to the particles of water in each container. This can be
done as annotated diagrams.
45
| Strengthening teaching and learning of particles in Key Stage 3 science | Session 2
| Notes for tutors
© Crown copyright 2003