3.5 Ways of transferring thermal energy [Mastery check]

Match the following

• convection

• Thermal energy is transferred but does not require matter to travel through.

• radiation

• Thermal energy causes a liquid or gas to expand so that hotter parts of the liquid or gas rise, and the cooler parts sink.

• conduction

• Thermal energy passes through a substance from particle to particle.

The three states of matter are solids, liquids and gases. List the three states in order so the best conductor is first and the worst conductor is last.

​ (a)   ​ (b)   ​ (c)  

• solid
• liquid
• gas

List the three states in order so the best substance for convection is first and the worst is last.

​ (a)   ​ (b)   ​ (c)  

• gas
• liquid
• solid

The electric kettle heats up the water at the bottom. Name the process by which the hotter water moves around the kettle.

The electric heater gets hot, heat is transferred from the heater to the water by ​ (a)   , particles in water around the heater vibrate more vigorously and take up more space, water around the heater ​ (b)   and become ​ (c)   , this hotter water ​ (d)   to the top of the tank, cooler water moves to the bottom of the heater to replace the water that has risen; this sets up a ​ (e)   that heats all the water.

• conduction
• expands
• less dense
• floats
• convection current

There are ways that thermal energy can be transferred from one place to another. Which two of these ways cannot occur in a vacuum.

• Conduction

• Convection

• Radiation

​ (a)   occurs best in solids because the particles in solid are ​ (b)   together to transferred the thermal energy from vibration.

• Conduction
• close
• Convection
• loose

Convection cannot occur in a ​ (a)   because the particles are not free to move.

• solid
• liquid
• gas

If an object that is hotter than its surroundings needs to lose heat quickly, it should have a ​ (a)   and ​ (b)   surface because such a surface is a good emitter of radiation.

• dull
• black
• shiny
• white

To reduce heat loss by radiation from an object that is hotter than its surroundings, the object should have a ​ (a)   and ​ (b)   surface because such a surface is a poor emitter of radiation.

• shiny
• silvery
• black
• dull