Topic 3 - Particle model of matter

Question 1

Describe the mass changes that take place when a unit changes state?

Answer 1

Mass is conserved:

- nothing is lost in a closed system

Question 2

What is a solid?

Answer 2

A solid is a substance with a fixed shape and volume, it is more dense than gases and liquids. it cannot flow, It’s particles can only vibrate. It cannot be compressed. It’s particles are very close together and are fixed in a rigid arrangement

Question 3

What is a liquid?

Answer 3

A liquid is a substance with no fixed shape but with a fixed volume, they are less dense than a solid but more dense than a gas. They can flow. They cannot be compressed. It’s particles are close together but are not fixed in a rigid arrangement, they are free to move

Question 4

What is a gas?

Answer 4

A gas is a substance with no fixed shape or volume, it is less dense than solids and liquids and it can flow. It can be compressed. It’s particles are far apart.

Question 5

What is the change from solid to liquid called?

Answer 5

melting

Question 6

What is the change from liquid to solid called?

Answer 6

freezing

Question 7

What is the change from liquid to gas called?

Answer 7

vaporisation

Question 8

What is the change from gas to liquid called?

Answer 8

condensing

Question 9

What is the change from gas to solid called?

Answer 9

deposition

Question 10

What is the change from solid to gas called?

Answer 10

sublimation

Question 11

What type of change is a change in state?

Answer 11

Physical changes, which differ from chemical changes because the material recovers its original properties if the change is reversed.

Question 12

What is internal energy?

Answer 12

The total kinetic energy and potential energy of all the particles (atoms and molecules) that make up a system.

Question 13

How does heating change the energy stored within a system?

Answer 13

By increasing the energy of the particles that make up the system. This either raises the temperature of the system or produces a change of state.

Question 14

What is the definition of specific latent heat?

Answer 14

The amount of energy required to change the state of one kilogram of the substance with no change in temperature.

Question 15

Describe what happens to energy supplied during a change in state.

Answer 15

When a change of state occurs, the energy supplied changes the internal energy but not the temperature.

Question 16

What is the definition of specific latent heat?

Answer 16

The amount of energy required to change the state of 1kg of the substance with no change in temperature.

Question 17

What is the specific latent heat of fusion?

Answer 17

The specific latent heat for changing between a solid & a liquid

Question 18

What is the specific latent heat of vaporisation?

Answer 18

The specific latent heat for changing between a liquid & a gas