| name | Cesium |
| latin | Caesium |
| french | Césium |
| german | Caesium |
| symbol | Cs |
| proton number | 55 |
| atomic weight | 132.90545 |
| Pauling electronegativity | 0.79 |
| electronic configuration | [Xe] 6s1 1s22s22p63s23p63d104s24p64d105s25p66s1 |
| melting point | 301.59 K, 28.44°C, 83.19°F |
| boiling point | 944 K, 671°C, 1240°F |
| group | 1 |
| period | 6 |
| state (by 20°C) | solid |
| oxidation states | +1 |
| Year of discovery | Discoverers |
| 1860 | Robert W. Bunsen (1811-1899) Gustav R. Kirchhoff (1824-1887) |