name | Helium |
latin | Helium |
french | Hélium |
german | Helium |
symbol | He |
proton number | 2 |
atomic weight | 4.002602 |
Pauling electronegativity | - |
electronic configuration | 1s2 |
melting point | 0.95 K, -272.2°C, -457.96°F |
boiling point | 4.22 K, -268.93°C, -452.07°F |
group | 18 |
period | 1 |
state (by 20°C) | gas |
oxidation states | - |
Year of discovery | Discoverers |
1868 | Pierre Janssen (1824-1907) |
1895 | Sir William Ramsay (1852-1916) and independently Nils Abraham Langlet (1868-1936) and Per Teodor Cleve (1840-1905) |