Question

Which phase change is an example of an exothermic process?

Answer 1

The question is unfortunately incomplete so it would be difficult to help you.

I can however by reminding you of the definition of an exothermic process.
A exothermic reaction is one that releases energy as heat. An example could include combustion reactions.

Answer 2

Forming bonds is another example of exothermic process

Answer 3

gas --> liquid --> solid are exothermic.
To move from solid --> liquid --> gas these phase transitions are endothermic in that they require an input of energy.