Compare Hydrogen vs Cesium
Comparing Hydrogen (H) and Cesium (Cs). Atomic numbers 1 and 55 with atomic masses 1.008 u and 132.905 u, classified as nonmetal and alkali metal. Below: a side-by-side comparison of their physical, atomic, electron-configuration and historical properties, including density, melting and boiling points, ionization energies, oxidation states and discovery history.
Periodic properties of the elements
| Hydrogen | Cesium | |
|---|---|---|
| Symbol | H | Cs |
| Atomic number | 1 | 55 |
| Group | 1 | 1 |
| Period | 1 | 6 |
| Block | s | s |
| Element category | Nonmetal | Alkali Metal |
Physical properties
| Hydrogen | Cesium | |
|---|---|---|
| Phase at STP | Gas | Solid |
| Density | 0.08988 g/cm3 | 1.93 g/cm3 |
| Atomic weight | 1.0079 u | 132.905 u |
| Melting point | 13.99 K -259.16 °C -434.488 °F | 301.7 K 28.55 °C 83.39 °F |
| Boiling point | 20.271 K -252.879 °C -423.1822 °F | 944 K 670.85 °C 1239.53 °F |
Atomic properties
| Hydrogen | Cesium | |
|---|---|---|
| Electronegativity (Pauling Scale) | 2.2 | 0.79 |
| Electron affinity | 72.769 kJ/mol | 45.505 kJ/mol |
| Oxidation states | −1, +1 (an amphoteric oxide) | −1, +1 (a strongly basic oxide) |
| Ionization energies |
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Electron configuration
| Hydrogen | Cesium | |
|---|---|---|
| Shorthand configuration | 1s1 | [Xe] 6s1 |
| Full configuration | 1s1 | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 6s1 |
| Electrons per shell | 1 | 2, 8, 18, 18, 8, 1 |
History
| Hydrogen | Cesium | |
|---|---|---|
| Discovery | Henry Cavendish (1766) | Robert Bunsen, Gustav Kirchhoff (1860) |
| First isolation | Henry Cavendish (1766) | Carl Setterberg (1882) |
| Named by | Antoine Lavoisier (1783) |