Fact 1: Boiling means change from a liquid into a gas by adding heat energy.

Fact 2: Boiling is the very rapid conversion of a liquid into vapor by the violent evolution of bubbles.

Given the two facts above, answer the question "What means a change from a liquid into a gas by adding heat energy?" with the following options: 
- Evaporation of water
 - heat is produced
 - violent evolution of bubbles
 - igniting fuel and oxidiser
 - Water expanding
 - a hemisphere is tilted away from the sun
 - evaporative cooling
 - degrees Celsius


 

   violent evolution of bubbles      