Atomic Properties
- Atomic Number
- 34
- Atomic Mass
- 78.9710 u
- Electron Configuration
- [Ar] 3d10 4s2 4p4
- Electronegativity
- 2.55
- Block
- p-block
- Group
- 16
- Period
- 4
Physical Properties
- Phase (STP)
- solid
- Melting Point
- 494.00 K
- Boiling Point
- 958.00 K
- Density
- 4.8100 g/cm³
About Selenium
Essential trace element; used in electronics and glass production.
Isotopes of Selenium
Selenium has 6 naturally occurring isotopes.
| Isotope | Mass Number | Atomic Mass (u) | Abundance | Type |
|---|---|---|---|---|
| 74Se | 74 | 73.92247593 | 0.8900% | Stable |
| 76Se | 76 | 75.9192137 | 9.370% | Stable |
| 77Se | 77 | 76.91991415 | 7.630% | Stable |
| 78Se | 78 | 77.91730928 | 23.77% | Stable |
| 80Se | 80 | 79.9165218 | 49.61% | Stable |
| 82Se | 82 | 81.9166995 | 8.730% | Stable |
Data source: NIH PubChem (aggregated from IUPAC, NIST)