| Attribute | Value |
|---|---|
| Symbol | Se |
| Standard state | Solid |
| Atomic mass | 78.97 u |
| Electron configuration | [Ar]4s²3d¹⁰4p⁴ |
| Oxidation states |
|
| Electronegativity (pauling scale) | 2.55 |
| Atomic radius (van der waals) | 190 pm |
| Ionization energy | 9.752 eV |
| Electron affinity | 2.021 eV |
| Melting point | 493.65 K |
| Boiling point | 958 K |
| Density | 4.809 g/cm³ |
| Atomic number | 34 |
| Group name | Nonmetal |
| Discovered | 1817 year |