Helium

Element 2 · Noble gas

Specimen

Atomic number
2
Atomic mass
4.0026
State at room temperature
Gas
Melting point
-272.2 °C
Boiling point
-268.9 °C
Density
0.0001785 g/cm³
Discovered
1868

Physical data from PubChem.1

Can I eat it?

In food and water
Allowed in food. The EU allows helium gas as food additive E 939, with no fixed maximum amount (quantum satis). 2

See every element.

The atom

He
ShellElectrons
1 (K) outermost 2
Total2

Configuration 1s²

1s ↑ ↓
A shell diagram: each ring is an electron shell and each dot is one electron. The nucleus holds 2 protons. The outermost shell is shown in red. Electrons do not travel on rings: they fill orbitals, regions where an electron is likely to be found. The boxes are those orbitals for the electrons outside the nucleus, with one arrow per electron.

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Sources

  1. 1

    National Center for Biotechnology Information (PubChem), 2026. Periodic Table of Elements .

    Atomic mass, electron configuration, melting and boiling points, density and discovery year for all 118 elements.

  2. 2

    European Commission, 2011. Commission Regulation (EU) No 1129/2011 establishing a Union list of food additives , Annex, Parts B and E.

    The text as adopted by the EU in 2011, from legislation.gov.uk. Later EU amendments are not in it.

    • E 939 Helium quantum satis