Oxygen turns into a pale blue liquid or solid when it is frozen.

Oxygen becomes a liquid at temperatures below -183 degrees Celsius (-297 degrees Fahrenheit). The blue color happens because of how oxygen molecules interact with light. When two oxygen molecules collide, they absorb a single particle of light called a photon. This absorption happens in the red part of the light spectrum, which leaves only the blue light for us to see.Scottish chemist James Dewar first studied this blue color in 1885. Liquid oxygen is also magnetic. It has two unpaired electrons that act like tiny magnets. If you pour the liquid between two strong magnets, it will stick to them and hang in the air.Oxygen freezes into a solid at -218.79 degrees Celsius (-361.82 degrees Fahrenheit). It stays blue even as a solid crystal. This liquid is very heavy and dense. Engineers use it as fuel for rockets like the SpaceX Falcon 9. It helps the rocket burn fuel in space where there is no air.