States of Matter

Question 1

Define matter.

1 mark

Answer 1

Matter is anything that occupies space and has a mass.

Question 2

Distinguish between the three states of matter in terms of their particle arrangement.

9 marks

Answer 2

Solids
* Rigid
* Fixed shape
* Fixed volume

Liquids
* Not rigid
* No fixed shape
* Fixed volume

Gases
* Not rigid
* No fixed shape
* No fixed volume

Question 3

What is a physical change?

2 marks

Answer 3

A physical change has no new products and is easy to reverse, e.g. a change in state of matter.

Question 4

Define melting, boiling, evaporation, condensation, freezing and sublimation.

6 marks

Answer 4

• Melting is when a solid changes into a liquid.
• Boiling is when a liquid changes into a gas.
• Evaporation is when a liquid changes into a gas.
• Condensation is when a gas turns into a liquid.
• Freezing is when a liquid changes into a solid.
• Sublimation is when a solid changes into a gas e.g. dry ice.

Question 5

Define a boiling and melting point.

4 marks

Answer 5

A boiling point is the temperature at which a liquid boils or a gas condenses. A melting point is the temperature at which a solid melts or a liquid freezes.

Question 6

1)………. , usually 2)………. , is requred for a change of state to occur.

2 marks

Answer 6

1. Energy
2. Thermal

Question 7

Define diffusion.

2 marks

Answer 7

Diffusion is the movement of a substance from an area of high concentration to an area of low concentration. Diffusion happens in liquids and gases because their particles move randomly from place to place.

Question 8

Describe gas pressure in terms of volume and temperature.

3 marks

Answer 8

The pressure of a gas is a factor of its volume and its temperature.
The higher the volume, the higher the pressure.
The higher the temperature, the higher the pressure.