Is helium soild liquid or gas?
Depends on the temperature and pressure of the gas. The boiling point of Helium (He) is about 4 K (or -269 C) at 1 atmospheric pressure. At room temperature (and for temperatures as low as 4 K) and normal atmospheric pressure, He is a gas. Below 4 K at 1 atmosphere, He is a liquid. Increasing the gas pressure will raise the boiling point — the gas-liquid transition temperature will be higher.
