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Questions on Energy Transitions

Q3. The back window of this car contains a heating element. The heating element is part of an electrical circuit connected to the battery of the car.

In very cold weather, ice may form on the back window of the car. When the heating element is switched on, the ice will disappear and the surface of the window will become clear and dry.

(i) Choose a word to fill the gap in the sentence below:

When the heater is switched on, ............thermal .......... energy is transferred from the wires to the ice.

When the heater is switched on chemical energy from the car's battery transfers to electrical energy in the wires; that electrical energy then transfers to thermal energy/heat within the wires - but you are not asked for those transfers - you are asked what transfers from the wires to the ice on the window - and that is the transfer of thermal/heat energy.

1 mark

(ii) As the window becomes clear and dry, physical changes take place in the ice.

Fill the gaps below to show the physical changes which take place.

The ice changes from a …solid……. to a ……liquid….to a ………gas OR vapour ………

All three states of matter in the correct order are required for the mark

1 mark

Total 2 marks