Helium - ASCII Periodic Table of the Elements

ASCII PERIODIC TABLE OF THE ELEMENTS

  He

Relative atomic mass: 4.002602 ± 0.000002

English: Helium
French: Hélium
Croatian: Helij
German: Helium
Italian: Elio
Spanish: Helio

Atomic number: 2
Group numbers: 18
Period: 1
Standard state (20 °C): gas

Discovery: 1868 Pierre Jules César Janssen (FR); Sir Joseph Norman Lockyer (GB)

Helium was discovered by Pierre Jules César Janssen (FR) and Sir Joseph Norman Lockyer (GB) in 1868. The origin of the name comes from the Greek word 'helios' meaning 'sun'. It is a light, odourless, colourless inert gas. Helium is the second most abundant element in the universe. Helium is found in natural gas deposits from wells in Texas, Oklahoma and Kansas. It is used in balloons, deep sea diving and welding and in very low temperature research.

Electronic configuration: 1s²
Formal oxidation number: 0
Atomic radius: 128 pm

Electronegativities: -
Thermal conductivity: 0.155 W/(m K)
Electrical resistivity (20 °C): - μΩcm

Melting point: -272.2 °C
Boiling point: -268.93 °C

Heat of fusion: 0.021 kJ/mol
Heat of vaporization: 0.082 kJ/mol
Heat of atomization: 0 kJ/mol