Convection, Conduction, Heat and Temperature

Question 1

1st stage of convection currents

Answer 1

the candle (or hot object) heats up the air

Question 2

2nd stage of convection currents

Answer 2

the hot air expands and so becomes less dense and begins to rise

Question 3

3rd stage of convection currents

Answer 3

cooler, more dense air sinks to replace the hot air and so forms a convection current

Question 4

density

Answer 4

=mass/volume

Question 5

conduction in solids

Answer 5

metals conduct heat at different rates

Question 6

conduction in liquids

Answer 6

water (liquid) is a poor conductor

Question 7

conduction in gases

Answer 7

gas is a poor conductor

Question 8

‘sea of electrons’

Answer 8

when metal is heated the ‘sea of electrons’ gains kinectic energy and it is transferred through the metal. insulators such as wood and plastic do not have a ‘sea of electrons, which is why the do not conduct as well as metals

Question 9

heat

Answer 9

a type of energy that will flow from a warm area to a colder one

Question 10

temperature

Answer 10

a measurement of how hot or cold an object is

Question 11

how is temperature determined?

Answer 11

it is determined by the average kinetic energy of the particles in an object

Question 12

when does heat transfer occur?

Answer 12

heat transfer occurs when there is a temperature difference between substances