Fact 1: Boiling means change from a liquid into a gas by adding heat energy.

Fact 2: Boiling water produces steam.

Given the two facts above, answer the question "What causes water to become steam?" with the following options: 
- Condensation
 - movement of tectonic plates
 - Increasing pressure
 - an engine
 - evaporation
 - heating liquids
 - Reducing temperature
 - Adding heat energy


 

        Adding heat energy 