Selenium Valence Electrons
Why selenium has 6
Selenium has 34 electrons, arranged as 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p4. The highest shell is n = 4, holding 4s2 4p4, so 2 + 4 = 6.
Selenium is in group 16; for groups 13–18 subtract 10 from the group number.
What that means for bonding
Selenium needs 2 more electrons to complete an octet, so it tends to gain 2 (forming Se2−) or share 2 in 2 covalent bonds.
Electrons per shell: 2, 8, 18, 6. See the selenium electron configuration and orbital diagram or the full selenium data sheet.
Same group, same count
Selenium valence electrons FAQ
How many valence electrons does selenium have?
Selenium has 6 valence electrons. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁴, and the outermost shell (n = 4) holds 4s² + 4p⁴.
How do you find the valence electrons of selenium?
Selenium is in group 16; for groups 13–18 subtract 10 from the group number.
How many bonds does selenium form?
Selenium needs 2 more electrons to complete an octet, so it tends to gain 2 (forming Se2−) or share 2 in 2 covalent bonds.
What is the Lewis dot structure of selenium?
The symbol Se with 6 dots around it, one per valence electron, placed singly on each side before any side is paired.
How many core electrons does selenium have?
28: 34 electrons in total minus the 6 valence electrons.