Potassium

Symbol | K
Latin name | Kalium
Atomic number | 19
Period | 4
Element category | Alkali metals
Relative atomic mass | 39.0983
Group | I.A
Electronegativity | 0.9
Oxidation numbers | 1
Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s1
Density [g/cm3] | 0.862
State | Solid
Melting point [°C] | 93.65
Boiling point [°C] | 760
Critical point [°C] | 1950
Critical pressure [MPa] | 16
Atomic radius [pm] | 243
Covalent radius [pm] | 196
Thermal conductivity [W m-1K-1] | 102.5
Heat capacity [J K-1g-1] | 0.757
Discovery | 1807
Hardness [Mohs scale] | 0.5
Brinell hardness [MPa] | 0.363
Electrical conductivity [S m-1] | 1.64 · 107
1.st ionization energy [eV] | 4.3407
2.nd ionization energy [eV] | 31.625
3.rd ionization energy [eV] | 45.72
Stable isotopes | 3
Unstable isotopes | 8