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

Fact 2: Hydrogen chloride is a gas.

Given the two facts above, answer the question "what will expand when heated?" with the following options: 
- chlorofluorocarbons
 - water vapor
 - graptolites
 - hydrogen chloride
 - deoxyribonucleic acid
 - flow of electrons
 - Calcium carbonate
 - an object


 

    hydrogen chloride     