Chlorine doesn't "turn into a gas" in the sense of a transformation. It's already a gas at room temperature and pressure.

Here's what's happening:

* Chlorine is a diatomic gas: This means it exists as a molecule with two chlorine atoms bonded together (Cl₂).

* At room temperature, chlorine is a greenish-yellow gas: The Cl₂ molecules are constantly moving and bouncing around, filling the space they occupy.

* Under pressure, chlorine can be liquefied: If you increase the pressure on chlorine gas, you force the Cl₂ molecules closer together. This reduces the space they have to move around in, and they eventually become a liquid.

* Chlorine can be solidified: By further increasing the pressure and decreasing the temperature, you can turn chlorine into a solid.

So, chlorine is already a gas under normal conditions. We can change its state by changing the pressure and temperature, but it's not undergoing a chemical transformation to become a gas.