No. Selenium is a nonmetal, classified as a reactive nonmetal on the periodic table.

How many protons does selenium have?

Selenium has 34 protons. Its atomic number is 34, which is also the number of electrons in a neutral atom of selenium.

What group and period is selenium in?

Selenium is in group 16 and period 4 of the periodic table, in the p-block.

What is the atomic mass of selenium?

The atomic mass of selenium is 78.971 u (unified atomic mass units).

Element 34

Selenium (Se)

Reactive nonmetal · Period 4 · Group 16 · p-block

Selenium (Se) is element 34 of the periodic table, a reactive nonmetal in period 4, group 16 (p-block) with an atomic mass of 78.971 and is a solid at standard conditions.

At a glance

Atomic number: 34
Symbol: Se
Atomic mass: 78.971 u
Category: Reactive nonmetals
Period: 4
Group: 16
Block: p-block
Phase at STP: solid

Electron structure

Electron configuration: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p4
Shorthand configuration: [Ar] 3d10 4s2 4p4
Electrons per shell: 2, 8, 18, 6
Oxidation states: -2, -1, +1, +2, +3, +4, +5, +6

Physical properties

Melting point: 494 K (220.85 °C)
Boiling point: 958 K (684.85 °C)
Density: 4.809 g/cm³
Phase: solid

Atomic properties

Electronegativity (Pauling): 2.55
Atomic radius: 103 pm
Covalent radius: 120 pm
Van der Waals radius: 190 pm
First ionization energy: 941 kJ/mol
Electron affinity: 195 kJ/mol

Notable isotopes

Notable isotopes of Selenium: mass number, atomic mass, natural abundance, and stability.
Isotope	Mass	Abundance	Stability
Se-80	79.91652	49.61%	Stable

Common uses

Glass making
Electronics
Solar cells
Supplements

Discovery

Year: 1817
Discovered by: Jöns Jacob Berzelius
Country: Sweden

Frequently asked questions

Is selenium a metal?: No. Selenium is a nonmetal, classified as a reactive nonmetal on the periodic table.
How many protons does selenium have?: Selenium has 34 protons. Its atomic number is 34, which is also the number of electrons in a neutral atom of selenium.
What group and period is selenium in?: Selenium is in group 16 and period 4 of the periodic table, in the p-block.
What is the atomic mass of selenium?: The atomic mass of selenium is 78.971 u (unified atomic mass units).

Keep exploring

Selenium's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.