Potassium
Alkali Metal
Potassium (K) is a chemical element with atomic number 19, classified as a alkali metal. At room temperature it is a solid. It was discovered in 1807 by Humphry Davy.
Properties
- Atomic number
- 19
- Atomic mass
- 39.098 u
- Category
- Alkali Metal
- Group
- 1
- Period
- 4
- Block
- s-block
- Electron configuration
- [Ar] 4s¹
- Phase at STP
- Solid
- Density
- 0.862 g/cm³
- Melting point
- 336.53 K (63.4 °C)
- Boiling point
- 1032 K (758.9 °C)
- Electronegativity
- 0.82
- Atomic radius
- 243 pm
- Ionization energy
- 4.341 eV
- Discovery
- 1807 · Humphry Davy
Common uses
Fertilizers, soap, explosives, salt substitute
Did you know?
So reactive it must be stored under oil and explodes violently in water.