Atomic Properties
- Atomic Number
- 1
- Atomic Mass
- 1.0080 u
- Electron Configuration
- 1s1
- Electronegativity
- 2.20
- Block
- s-block
- Group
- 1
- Period
- 1
Physical Properties
- Phase (STP)
- gas
- Melting Point
- 13.99 K
- Boiling Point
- 20.27 K
- Density
- 0.0001 g/cm³
About Hydrogen
Lightest element; most abundant in the universe; forms water with oxygen.
Isotopes of Hydrogen
Hydrogen has 2 naturally occurring isotopes, plus 1 notable radioactive isotope.
| Isotope | Mass Number | Atomic Mass (u) | Abundance | Type |
|---|---|---|---|---|
| 1H | 1 | 1.007825032 | 99.99% | Stable |
| 2H | 2 | 2.014101778 | 0.0115% | Stable |
| 3H | 3 | 3.016049278 | — | Radioactive |
Data source: NIH PubChem (aggregated from IUPAC, NIST)