H

Helium

He Elements CAS 7440-59-7
Quick Reference
Formula / NotationHe
CAS Number7440-59-7
Molecular Weight4.003
Also Known AsHe, helium gas, noble helium, alpha particle (nucleus)
CategoryElements

What is Helium?

Helium is the second lightest and second most abundant element in the universe. It is a colourless, odourless, non-toxic, inert noble gas with the lowest boiling point of any element.

Formula & Notation

He

Other Names / Synonyms: He, helium gas, noble helium, alpha particle (nucleus)

Properties & Characteristics

Appearance: colourless gas. Boiling point: −268.93 °C. Density (gas): 0.1786 g/L. Does not solidify at atmospheric pressure.

Uses & Applications

Cryogenic cooling for MRI magnets. Pressurising rocket fuel. Inert shielding gas in welding. Lifting gas for balloons. Carrier gas in chromatography.

Safety Information

Non-toxic and non-flammable. Asphyxiant in high concentrations. Pressurised container inhalation risk.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Helium
Formula He
CAS Number 7440-59-7
Molecular Weight 4.003
Category Elements
Synonyms He, helium gas, noble helium, alpha particle (nucleus)

Frequently Asked Questions

Helium is the second lightest and second most abundant element in the universe. It is a colourless, odourless, non-toxic, inert noble gas with the lowest boiling point of any element.

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