Heat Transfer

What happens to the molecules in a liquid as it gets hotter?

• They stay at the same speed

• They slow down

• They speed up

Which statement about convection is false?

• Convection occurs in solids

• Convection occurs in gases

• Convection occurs in liquids

Which statement about heat energy is true?

• Heat energy flows from a region of low temperature to a region of high temperature

• Heat energy does not flow

• Heat energy flows from a region of high temperature to a region of low temperature

What is the main reason that metals are good conductors?

• Vibrations pass from atom to atom transferring heat energy as they do so

• Metals can be heated to high temperatures

• Metals contain free electrons

What is an insulator?

• A material that allows heat energy to follow through it easily

• A material that will not allow heat energy to flow through it easily

• A metal

What would make the best material for wrapping around a mug to keep a hot drink warm for as long as possible?

• Copper foil

• Bubble wrap

• Aluminium foil

What happens to the molecules in a solid as it gets hotter?

• Vibrate slower

• Start vibrating

• Vibrate faster

Which statement is true about a dull, matt surface?

• A dark, matt surface is better at absorbing heat energy than a light shiny surface

• A dark, matt surface is worse at absorbing heat energy than a light shiny surface

• A dark matt surface is worse at radiating heat energy than a light shiny surface

Why is loft insulation so effective?

• It is itchy but reduces noise in the loft

• The fibres do not burn easily if there is a fire

• It traps air which helps to reduce heat lost from the home

How much energy will a 30 W heater provide in 5 minutes?

• 6 J

• 150 J

• 9000 J