Helium
Formula : He
CAS :
7440-59-7
A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics.
Helium, crude
Formula : Unspecified
CAS :
68511-78-4
TSCA Definition 2019: Complex combination of helium and nitrogen separated from natural gas by chilling. Contains approximately 65% nitrogen.
Helium, ion (He4(1+))
Formula : He4
CAS :
12596-23-5