Question: Is it possible for gas to turn to a solid?

Claudia Krehl answered on 13 Mar 2013:

You can indeed. Dry ice is a very good example, as it is solid carbon dioxide. You can turn gas directly into a solid as long as the pressure is low enough. For example, you could start with the gas compressed and then suddenly release the pressure (as when you use a carbon dioxide fire extinguisher). That produces at the same time the low enough pressure and the low enough temperature for the gas to turn solid without first becoming liquid, and you can actually see the flakes of solid that form.