34 Se
Reactive nonmetal
Selenium
Used in solar cells.
Properties of Selenium
- Atomic number (Z)
- 34
- Symbol
- Se
- Atomic mass
- 78.971 g/mol
- Category
- Reactive nonmetal
- Group
- 16
- Period
- 4
- Electron configuration
- [Ar] 3d¹⁰ 4s² 4p⁴
- Electronegativity (Pauling)
- 2.55
- Atomic radius
- 103 pm
- First ionization energy
- 941 kJ/mol
- Melting point
- 453 K (179.9 °C)
- Boiling point
- 958 K (684.9 °C)
- Density
- 4.809 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1817
Frequently asked questions
What is Selenium?
Selenium (Se) is a reactive nonmetal, element number 34 on the periodic table. Used in solar cells.
What is the atomic number and atomic mass of Selenium?
Selenium has atomic number 34 and an atomic mass of about 78.971 g/mol.
What is the electron configuration of Selenium?
The electron configuration of Selenium is [Ar] 3d¹⁰ 4s² 4p⁴.
Where is Selenium on the periodic table?
Selenium sits in group 16, period 4, and is classified as a reactive nonmetal.