Heating And Cooling

Question 1

How can heat be transferred?

Answer 1

Convection
Conduction
Radiation

Question 2

Kinetic theory of a solid?

Answer 2

Arrangement of particles -close together in a regular pattern
Movement of particles-
Vibrate in fixed position

Question 3

Kinetic theory of a liquid?

Answer 3

Arrangement of particles-
Close together but random pattern
Movement of particles-
Move around eachother

Question 4

Kinetic theory of a gas

Answer 4

Arrangement of particles - far apart and random
Movement of particles-
Move quickly in any direction

Question 5

Which states of matter cannot be compressed ?

Answer 5

Liquids and solids

Question 6

What is a good conductor?

Answer 6

Metals

Question 7

What do you call a poor conductor of heat?

Answer 7

Insulator

Question 8

What happens in conduction (6 marks)

Answer 8

The ELECTRONS leave their ATOMS and become FREE ELECTRONS

the parts of the atoms left behind are now CHARGED METAL IONS

this vibrate continually

The hotter the metal , the more KINETIC ENERGY the vibrations have

The kinetic energy goes from the hot to cool parts of a metal by FREE ELECTRONS whilst colliding with IONS

Question 9

What is a conductor?

Answer 9

Material through which energy is transferred easily

Question 10

What is an insulator?

Answer 10

Material through which the speed of transfer of energy is reduced

Question 11

What happens in convection currents?

Answer 11

Heat applied so particles gain energy

Fluid expands

Less dense particles rise to the top

More dense particles drop to the bottom

BOOM CONVECTION CURRENT

Question 12

What is evaporation?

Answer 12

Liquid to gas

Question 13

What is condensation?

Answer 13

Gas to liquid

Question 14

What factors affect the rate of condensation and evaporation ?

Answer 14

Surface area of the liquid

If air is moving over the surface of a liquid

Question 15

How does an animal reduce heat loss?

Answer 15

Have a small surface area to volume ratio

Question 16

What is a u value?

Answer 16

Shows How effective of an insulator something is

Question 17

What is the rule with u values ?

Answer 17

Lower the u value , the better the insulator

Question 18

What do solar panels do? (4 marks)

Answer 18

Heat energy is taken from the sun

Cold water is pumped to the solar panel

The water is heated by the heat energy in the sun

This then returns to the tank

Question 19

Advantages of solar panels?

Answer 19

Renuable

No pollution

Question 20

Disadvantages of solar panels?

Answer 20

Don’t work at night

Only very hot in the summer

Question 21

What is the difference between temperature and heat?

Answer 21

Temperature (*c) measures how hot something is

Heat (j) measures the amount of thermal energy in an object

Question 22

What does temperature increase depend on?

Answer 22

Mass
Substance
Amount of energy transferred

Question 23

More energy transferred means…

Answer 23

… Higher the temperature

Question 24

What is specific heat capacity ?

Answer 24

Amount of thermal energy needed to raise the temperature of a 1kg substance by 1*c