Compare Helium vs Beryllium
Comparing Helium (He) and Beryllium (Be). Atomic numbers 2 and 4 with atomic masses 4.003 u and 9.012 u, classified as noble gas and alkaline earth 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
| Helium | Beryllium | |
|---|---|---|
| Symbol | He | Be |
| Atomic number | 2 | 4 |
| Group | 18 | 2 |
| Period | 1 | 2 |
| Block | s | s |
| Element category | Noble Gas | Alkaline Earth Metal |
Physical properties
| Helium | Beryllium | |
|---|---|---|
| Phase at STP | Gas | Solid |
| Density | 0.1786 g/cm3 | 1.85 g/cm3 |
| Atomic weight | 4.0026 u | 9.01218 u |
| Melting point | 0.95 K -272.2 °C -457.96 °F | 1560 K 1286.85 °C 2348.33 °F |
| Boiling point | 4.222 K -268.928 °C -452.0704 °F | 2742 K 2468.85 °C 4475.93 °F |
Atomic properties
| Helium | Beryllium | |
|---|---|---|
| Electronegativity (Pauling Scale) | 0 | 1.57 |
| Electron affinity | -48 kJ/mol | -48 kJ/mol |
| Oxidation states | 0 | 0, +1, +2 (an amphoteric oxide) |
| Ionization energies |
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Electron configuration
| Helium | Beryllium | |
|---|---|---|
| Shorthand configuration | 1s2 | [He] 2s2 |
| Full configuration | 1s2 | 1s2 2s2 |
| Electrons per shell | 2 | 2, 2 |
History
| Helium | Beryllium | |
|---|---|---|
| Discovery | Pierre Janssen, Norman Lockyer (1868) | Louis Nicolas Vauquelin (1798) |
| First isolation | William Ramsay, Per Teodor Cleve, Abraham Langlet (1895) | Friedrich Wöhler, Antoine Bussy (1828) |
| Named by | Edward Frankland, Norman Lockyer (1868) |