Thallium Valence Electrons
Why thallium has 3
Thallium has 81 electrons, arranged as 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p1. The highest shell is n = 6, holding 6s2 6p1, so 2 + 1 = 3.
Thallium is in group 13; for groups 13–18 subtract 10 from the group number.
What that means for bonding
As a metal, thallium tends to lose valence electrons rather than gain them, forming Tl+ or Tl3+ ions.
Electrons per shell: 2, 8, 18, 32, 18, 3. See the thallium electron configuration and orbital diagram or the full thallium data sheet.
Same group, same count
Thallium valence electrons FAQ
How many valence electrons does thallium have?
Thallium has 3 valence electrons. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p¹, and the outermost shell (n = 6) holds 6s² + 6p¹.
How do you find the valence electrons of thallium?
Thallium is in group 13; for groups 13–18 subtract 10 from the group number.
How many bonds does thallium form?
As a metal, thallium tends to lose valence electrons rather than gain them, forming Tl+ or Tl3+ ions.
What is the Lewis dot structure of thallium?
The symbol Tl with 3 dots around it, one per valence electron, placed singly on each side before any side is paired.
How many core electrons does thallium have?
78: 81 electrons in total minus the 3 valence electrons.