Arsenic Valence Electrons
Why arsenic has 5
Arsenic has 33 electrons, arranged as 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p3. The highest shell is n = 4, holding 4s2 4p3, so 2 + 3 = 5.
Arsenic is in group 15; for groups 13–18 subtract 10 from the group number.
What that means for bonding
Arsenic needs 3 more electrons to complete an octet, so it tends to gain 3 (forming As3−) or share 3 in 3 covalent bonds.
Electrons per shell: 2, 8, 18, 5. See the arsenic electron configuration and orbital diagram or the full arsenic data sheet.
Same group, same count
Arsenic valence electrons FAQ
How many valence electrons does arsenic have?
Arsenic has 5 valence electrons. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p³, and the outermost shell (n = 4) holds 4s² + 4p³.
How do you find the valence electrons of arsenic?
Arsenic is in group 15; for groups 13–18 subtract 10 from the group number.
How many bonds does arsenic form?
Arsenic needs 3 more electrons to complete an octet, so it tends to gain 3 (forming As3−) or share 3 in 3 covalent bonds.
What is the Lewis dot structure of arsenic?
The symbol As with 5 dots around it, one per valence electron, placed singly on each side before any side is paired.
How many core electrons does arsenic have?
28: 33 electrons in total minus the 5 valence electrons.