You are presented with the question "boiling is changing from a liquid to a gas by adding what?" and the following answer choices: 
- Joules
 - ice
 - warmth
 - air
 - water
 - forces
 - light
 - digestion

Now knowing that boiling means change from a liquid into a gas by adding heat energy and heat is Energy and is measured in Joules, choose the best answer.


 

 Joules        