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 |