Page 43 - 新思维科学学生用书7 样章

2 Materials and their structure

4 Use particle theory to explain how a liquid changes to a gas.
5 Use particle theory to explain how a liquid changes to become a solid.

6 Use particle theory to explain what happens when steam in the bathroom hits a cold surface,
such as a mirror.
7 Copy this flow chart. The arrows represent the processes involved when matter changes state.

Add the name for each process, A–D.
solid liquid gas

A ……….….... B ……….…....

solid liquid gas

C ……….….... D ……….…....

Think like a scientist

Modelling changes of state

In this task, your class will model the changes of state by arranging yourselves as
particles. You will need a lot of space.
Solid to liquid

• As a class, arrange yourselves as if you are the particles in a solid.
• Imagine the particles are being heated. Move as if you are being heated gently.
Move as the particle theory suggests you should.
• Imagine the particles are now being heated strongly, so that the solid melts and

becomes a liquid. Remember to behave as the particle theory suggests you
should.

Question
1 Describe how you had to act to illustrate the behaviour of particles as a solid
melts. Think about how you behaved. Was the model a good or a bad model for
particle theory? Explain.

Liquid to gas
• As a class, arrange yourselves as if you are the particles in a liquid.

• Imagine the particles are being heated. Move as if you are being heated gently.
• Imagine the particles are now being heated strongly so that the liquid boils.
Remember to behave as the particle theory suggests you should.

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