You are presented with the question "What happens to the density of a gas when heated?" and the following answer choices: 
- stays constant
 - Temperature
 - energy
 - Energy.
 - decreases
 - nothing
 - Evaporation
 - increases

Now knowing that if gas is heated then that gas will expand and if a material is heated, it expands and the density decreases, choose the best answer.


 

     decreases    