Helium

Helium 4.002602(2)   He 2 [ ? ] Noble gas: Properties: Metallic Uses: Balloons, Many scientific uses.

Helium is a chemical element, having the chemical symbol He.

Helium 4.002602(2)   He 2 1s2 [ ? ] Noble gas:

Its atomic number (the number of protons) is 2. It has a Standard Atomic Weight of 4.002602(2), and is typically found as a gas in its elemental form.

Helium is considered to be a member of the "Noble gas" class of elements, has a boiling point of -268.93 °C , and a melting point of -272.2 °C .