Heat

Question 0

What happens when we heat a solid, liquid or gas?

Answer 0

It expands.

Question 1

Heat:

Answer 1

Is a form of energy.

Question 2

What happens when we cool a solid, liquid or gas?

Answer 2

It contracts.

Question 3

Heat transfer:

Answer 3

Heat is transferred by 3 methods:

1. Convection.
2. Conduction.
3. Radiation.

Question 4

Conduction:

Answer 4

Heat travels from particle to particle along a substance, normally a solid.

Question 5

Convection:

Answer 5

Heat travels through a fluid (liquid or a gas) when the particles move and carry the heat.

Question 6

Radiation:

Answer 6

Heat travels from a hot object without the need for a medium, does not need a solid, liquid or gas to go through, will flow through a vacuum

Question 7

Conductor:

Answer 7

Something that allows energy e.g. Heat to flow through it. E.g. Metal is a good conductor.

Question 8

Insulator:

Answer 8

An insulator is a substance that doesn’t allow heat to flow through it easily e.g. Plastic.

Question 9

To show when a solid expands when heated and contracts when cooled.

Answer 9

Ball and ring apparatus.

Question 10

Water:

Answer 10

Begins to expand when cooled below 4 degrees Celsius e.g. Iceberg

Question 11

Air:

Answer 11

Is a good insulator, keeps animals warm, is trapped by the fur that helps to insulate the animal.

Question 12

Layers:

Answer 12

The hairs on our arms are not very good at keeping us warm, if we wear layers of clothes the air between the layers is trapped to keep us warm.

Question 13

Winds are formed by convection

Answer 13

The sun heats the earth. This causes hot air to rise, as the hot air rises it cools and sinks down to the ground.

Question 14

Winds are formed by convection

Answer 14

The sun heats the earth. This causes hot air to rise, as the hot air rises it cools and sinks down to the ground.

Question 15

Temperature

Answer 15

A measure of how hot an object is.

Question 16

Thermometer

Answer 16

The liquid in the thermometer will expand and rise when heated and will contract and fall when cooled.

Question 17

Boiling point of water…

Answer 17

100°C

Question 18

Freezing point of water…

Answer 18

0°C

Question 19

Melting point

Answer 19

Is when a solid turns to a liquid.

Question 20

Boiling point

Answer 20

Is when a liquid turns into a gas.

Question 21

Freezing point

Answer 21

Is when a liquid turns into a solid.

Question 22

Condensation

Answer 22

Is a gas turning into a liquid.

Question 23

Evaporation

Answer 23

Is when a liquid turns into a gas.

Question 24

Pressure & Boiling point: A kettle will normally boil at 100°C, but it will boil at 70°C on top of Mt.Everest.

Answer 24

Atmospheric pressure is less so it is easier for the water vapour to escape.

Question 25

Latent Heat

Answer 25

The heat taken in or given out when a substance is changing state without a change in temperature.

Question 26

Latent heat of fusion

Answer 26

Is used when a solid changes into a liquid.

Question 27

Latent heat of vaporisation

Answer 27

Is used when a liquid changes to a gas.

Question 28

Unit

Answer 28

All energy is a joule.

Question 29

Dull, black surface radiates..

Answer 29

Heat better than a shiny surface.

Question 30

Dull, black surface absorbs..

Answer 30

Heat better than a shiny surface.

Question 31

The amount of heat in a substance depends on:

Answer 31

Temperature, mass and what it is made of e.g. 200 ml of water at 60°C has twice as much heat as 100 ml of water at 60°C.