Cesium

Symbol | Cs
Latin name | Caesium
Atomic number | 55
Period | 6
Element category | Alkali metals
Relative atomic mass | 132.90543
Group | I.A
Electronegativity | 0.7
Oxidation numbers | 1
Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 6s1
Density [g/cm3] | 1.873
State | Solid
Melting point [°C] | 28.40
Boiling point [°C] | 700
Critical point [°C] | 1665
Critical pressure [MPa] | 9.4
Atomic radius [pm] | 298
Covalent radius [pm] | 225
Thermal conductivity [W m-1K-1] | 35.9
Heat capacity [J K-1g-1] | 0.24
Discovery | 1860
Hardness [Mohs scale] | 0.2
Young's modulus [GPa] | 1.7
Electrical conductivity [S m-1] | 5.3 · 106
1.st ionization energy [eV] | 3.8939
2.nd ionization energy [eV] | 25.10
Stable isotopes | 2
Unstable isotopes | 19