Page 70 - 新思维科学学生用书7 样章

2 Materials and their structure

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2.1 Which state of matter has the strongest forces between its particles? [1]
2.2 Name the state of matter that fits each description.
a Particles do not touch one another. [1]

b Particles are close together in a regular pattern. [1]
c Particles are closely packed but not in a regular pattern. [1]
2.3 Water in a puddle on a pathway disappears on a warm day. Explain what

happens to the water particles. [2]
2.4 a Which are the two correct statements about liquids? [2]
i Liquids can flow and be poured into a container.
ii The particles in liquids are far apart.
iii The particles in liquids are arranged randomly.

iv The particles in a liquid can only vibrate.
v Liquids only form at temperatures above 100 °C.
b A liquid changes to a solid when it freezes.

Describe what happens to the particles during this process. [2]
2.5 Which of these terms matches the two facts?

precipitation evaporation condensation groundwater

a This falls from clouds.
Rain, snow and hail are forms of this. [1]
b This is what happens when water vapour cools down.

This is a change from water vapour to a liquid. [1]
c When this happens, liquid water changes to water vapour.
Water from rivers and the oceans is taken up into the atmosphere. [1]

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