Fact 1: Melting is when solids are heated above their melting point.

Fact 2: When melted or dissolved in water, the crystal lattice is destroyed and the ions move freely.

Given the two facts above, answer the question "What is when solids are heated and ions move freely?" with the following options: 
- dissolving
 - refreshing
 - kinetic energy
 - removing
 - boiling
 - barrel-shaped
 - renewing
 - unidirectional


 

 dissolving        