Fact 1: Adding salt to a solid decreases the freezing point of that solid.

Fact 2: Another name for salt is sodium.

Given the two facts above, answer the question "What can you add to a solid to lower its freezing point?" with the following options: 
- calcite
 - energy
 - heat
 - sodium
 - boiling
 - Solutions
 - salinity
 - Energy.


 

    sodium     