Fact 1: Phase changes do not change mass.

Fact 2: Melting, freezing, condensation, and evaporation are examples of phase changes.

Given the two facts above, answer the question "Melting matter does not change its " with the following options: 
- crust
 - metal
 - mass
 - O3
 - heat
 - cycles
 - energy
 - liquid


 

   mass      