55
Cs
caesium
cesium
132.91

General properties

Group
group 1 (H and alkali metals)
Period
period 6
Category
alkali metals
Standard atomic weight
132.905 451 96(6)
Melting point
301.7 K (28.6 °C)
Boiling point
944 K (671 °C)
Phase at STP
solid

Additional properties

Block
s-block
Electron configuration
[Xe] 6s¹
Electrons per shell
2, 8, 18, 18, 8, 1
Electronegativity
0.79
Density
1.93 g/cm³
Oxidation states
−1, +1 (a strongly basic oxide)
CAS Number
7440-46-2