Atomic number: 19
Density at 25°C: solid
Potassium is a highly reactive metal as an element and quite soft. However, as an ion K+, in biology, it is critical for many functions . It has the symbol K because it comes from the latin Kalium which means potash, which in turn is the alkali that comes from plants. Which is originally where it was used.
Use, natural applications or common combinations:
- For neurone cells transmitting information.
- minerals like carnallite, langbeinite, polyhalite
- Standard atomic weight: 39.0983(1)
- Melting point: 63.38 °C
- Boiling point: 759 °C
- Radioactivity: most are stable
- 40K is important for radio dating rock samples with a half life of 1.248×109 years major source of natural radioactivity in people (0.012%) decaying via beta-