Bromine Valence Electrons
Why bromine has 7
Bromine has 35 electrons, arranged as 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p5. The highest shell is n = 4, holding 4s2 4p5, so 2 + 5 = 7.
Bromine is in group 17; for groups 13–18 subtract 10 from the group number.
What that means for bonding
Bromine needs 1 more electron to complete an octet, so it tends to gain one (forming Br−) or share one in a single covalent bond.
Electrons per shell: 2, 8, 18, 7. See the bromine electron configuration and orbital diagram or the full bromine data sheet.
Same group, same count
Bromine valence electrons FAQ
How many valence electrons does bromine have?
Bromine has 7 valence electrons. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁵, and the outermost shell (n = 4) holds 4s² + 4p⁵.
How do you find the valence electrons of bromine?
Bromine is in group 17; for groups 13–18 subtract 10 from the group number.
How many bonds does bromine form?
Bromine needs 1 more electron to complete an octet, so it tends to gain one (forming Br−) or share one in a single covalent bond.
What is the Lewis dot structure of bromine?
The symbol Br with 7 dots around it, one per valence electron, placed singly on each side before any side is paired.
How many core electrons does bromine have?
28: 35 electrons in total minus the 7 valence electrons.