(hēʹlē-əm) noun. Symbol HeA colorless, odorless inert gaseous element occurring in natural gas and with radioactive ores. It is used as a component of artificial atmospheres and laser media, as a refrigerant, as a lifting gas for balloons, and as a superfluid in cryogenic research. Atomic number 2; atomic weight 4.0026; boiling point -268.9°C; density at 0°C 0.1785 gram per liter, helium.
helium liquafaction - pencairan helium
helium liquefier - pencecair helium