Potassium
Discovery date
1807
Discovered by
Humphry Davy
Origin of the name
The name is derived from the English word 'potash'.
Allotropes
K
Potassium
19
39.098
Fact box
Group
1
Melting point
63.5°C, 146.3°F, 336.7 K
Period
4
Boiling point
759°C, 1398°F, 1032 K
Block
s
Density (g cm−3)
0.89
Atomic number
19
Relative atomic mass
39.098
State at 20°C
Solid
Key isotopes
39K
Electron configuration
[Ar] 4s
1
CAS number
7440-09-7
ChemSpider ID
4575326
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