# What is the process by which a gas changes its state to become a liquid?

Nov 27, 2016

$\text{Condensation}$ describes the phase transition: $\text{gas "rarr" liquid}$

#### Explanation:

And thus $\text{steam}$, $\text{water vapour}$, condenses to liquid water:

${H}_{2} O \left(g\right) \rightarrow {H}_{2} O \left(l\right) + \Delta$

The process as written is exothermic, and of course the condensation reaction can be used to drive a steam engine.