Helium vs Lithium
Side-by-side comparison of Helium (He, element 2) and Lithium (Li, element 3) by atomic structure and physical properties.
| | |
|---|
| Atomic number | 2 | 3 |
|---|
| Symbol | He | Li |
|---|
| Name | Helium | Lithium |
|---|
| Category | noble-gas | alkali-metal |
|---|
| Standard Atomic Weight | 4.002602 u | 6.9675 u |
|---|
| Period | 1 | 2 |
|---|
| Group | 18 | 1 |
|---|
| Block | s | s |
|---|
| Phase at STP | Gas | Solid |
|---|
| Electron configuration | 1s2 | [He]2s1 |
|---|
| Oxidation states | [0] | [1] |
|---|
| Electronegativity (Pauling) | N/A | 0.98 |
|---|
| Electron affinity | -0.5 eV | 0.61804 eV |
|---|
| Density | 0.1785 kg/m³ | 534 kg/m³ |
|---|
| Melting point | -272.2 °C | 180.5 °C |
|---|
| Boiling point | -268.93 °C | 1341.85 °C |
|---|
| Discovery year | 1868 | 1817 |
|---|
Key Differences
| He Helium | Li Lithium |
|---|
| Standard Atomic Weight | 4.002602 u ↓ lower | 6.9675 u ↑ higher |
|---|
| Density | 0.1785 kg/m³ ↓ lower | 534 kg/m³ ↑ higher |
|---|
| Melting point | -272.2 °C ↓ lower | 180.5 °C ↑ higher |
|---|
| Boiling point | -268.93 °C ↓ lower | 1341.85 °C ↑ higher |
|---|
| Electron affinity | -0.5 eV ↓ lower | 0.61804 eV ↑ higher |
|---|
| Period | 1 | 2 |
|---|
| Group | 18 | 1 |
|---|
| Category | noble-gas | alkali-metal |
|---|
| Phase at STP | Gas | Solid |
|---|
| Electron configuration | 1s2 | [He]2s1 |
|---|
| Discovery year | 1868 | 1817 |
|---|