Oxygen exists in a gaseous state at room temperature. With a boiling point of minus 297 degrees Fahrenheit, oxygen exists in its gaseous state on Earth almost all of the time unless it is deliberately liquefied.
Oxygen transitions from liquid to solid at minus 361 degrees Fahrenheit. Liquid oxygen can actually be produced using a cylinder of oxygen gas, a tank of liquid nitrogen and a small test tube. To produce liquid oxygen, place the test tube in a bath of liquid nitrogen and blow oxygen gas into the test tube. Because liquid nitrogen is colder than the boiling point of oxygen, these conditions cause the oxygen to condense in the test tube. Liquid oxygen appears as a pale blue liquid.