Here's why:

* All elements can exist in all three states of matter (solid, liquid, gas) under the right conditions. The state of matter depends on temperature and pressure.

* Potassium is a highly reactive metal. It has a relatively low boiling point (759°C or 1400°F).

* At temperatures above its boiling point, potassium will vaporize and become a gas.

However, potassium gas is highly reactive and unstable. It would quickly react with oxygen and other components in the air, so it's not something you'd find naturally occurring.