You are presented with the question "Water vapor is formed when gas changes into a liquid by reducing what?" and the following answer choices: 
- direct energy
 - electrical energy
 - kinetic energy
 - heat energy
 - solar flares
 - Temperature
 - energy
 - water power

Now knowing that condensation is when change from a gas into a liquid by reducing heat energy and clouds form by the condensation of water vapor, choose the best answer.


 

    heat energy     