Cs
Caesium
Z 55 132.905 g/molAlkali Metal
Nucleus
55 Protons
78 Neutrons
55 Electrons (1 Valence)
Shell distribution: K2 • L8 • M18 • N18 • O8 • P1 • Q0
Electron Configuration
Energy
7p
6d
5f
7s
6p
5d
4f
6s
5p
4d
5s
4p
3d
4s
3p
3s
2p
2s
1s
[Xe]6s1
Oxidation States
CommonRare
0
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Radii
Empirical
260 pm2.6 Å
Calculated
298 pm2.98 Å
Covalent
244±11 pm2.44±0.11 Å
Van der Waals
343 pm3.43 Å
IonicCs+
167 pm1.67 Å
Crystal Structure
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Body-centered cubic
Pearson symbol
cI2
Space group
Im3m No. 229