Chlorine exists in different states of matter depending on the temperature and pressure:

* At room temperature and pressure, chlorine is a gas. It's a greenish-yellow gas with a strong, suffocating odor.

* At -34.04 °C ( -29.27 °F), chlorine becomes a liquid.

* At -101.5 °C (-150.7 °F), chlorine freezes into a solid.

Therefore, the most common state of matter for chlorine is gas.