Fact 1: If gas is heated then that gas will expand.

Fact 2: Chlorine is a type of Green Cross gas.

Given the two facts above, answer the question "what will expand when heated?" with the following options: 
- arteries
 - water vapor
 - breathing
 - viewing
 - condensation
 - a prism
 - glass
 - chlorine


 

        chlorine 