Helium vs Neon
| Property | He Helium | Ne Neon |
|---|---|---|
| Atomic number | 2 | 10 |
| Symbol | He | Ne |
| Name | Helium | Neon |
| Category | noble-gas | noble-gas |
| Standard Atomic Weight | 4.002602 u | 20.1797 u |
| Period | 1 | 2 |
| Group | 18 | 18 |
| Block | s | p |
| Phase at STP | gas | gas |
| Electron configuration | 1s2 | [He]2s22p6 |
| Oxidation states | [0] | [0] |
| Electronegativity (Pauling) | N/A | N/A |
| Electron affinity | -0.5 eV | -1.2 eV |
| Density | 0.1785 kg/m³ | 0.8999 kg/m³ |
| Melting point | -272.2 °C | -248.59 °C |
| Boiling point | -268.93 °C | -246.05 °C |
| Discovery year | 1868 | 1898 |