Fact 1: Alight bulb converts electrical energy into light energy when it is turned on.

Fact 2: Light energy is converted into heat energy.

Given the two facts above, answer the question "electrical energy is converted into" with the following options: 
- engines
 - Pollution
 - heat energy
 - sensory neurons
 - Firecrackers
 - animal transport
 - to move people
 - warmth


 

   heat energy      