| K | Potassium | Atomic number : 19 Relative atomic mass (12C = 12.0000) : 39.0983 |
|||||||
| P H Y S I C A L D A T A | |
| Group 1 alkali metal Density / kg m-3 : 862 [293 K]; 828 [liquid at m.p.] |
Melting point / K : 336.80 Boiling point / K : 1047 |
| D I S C O V E R Y | |
| Isolated in 1807 by Sir Humphry Davy at London, England. |
|
| G E O L O G I C A L D A T A | |
| Abundances Sun (relative to H = 1 × 1012) : 1.45 × 105 Earth's crust / p.p.m. : 21 000 Residence time / years : 5 × 106 Classification : accumulating Oxidation state : I |
Seawater / p.p.m. : |
| B I O L O G I C A L D A T A | |
| Level in humans Blood / mg dm-3 : 1620 Bone / p.p.m. : 2100 Liver / p.p.m. : 16 000 Muscle / p.p.m. : 16 000 |
Daily dietary intake : 1400 - 1700 mg Total mass of element in average (70 kg) person : 140 g |
 |
A portrait of potassium is available on the Visual Elements site. Up to 200 individual items of information on this element are available in The Elements. |