valence electrons

[Katherine Wu 1H]

Give the number of valence electrons (including d electrons) for each of the following elements:
a. Sb b. Si c. Mn d. B

I think I understand how to find the valence electrons for b, c, and d. Si: 4, Mn: 7, B: 3. I don't understand how the answer for a. (5 electrons) came to be?

[Anthony Hatashita 4H]

I'm not sure to be honest, but I think it has to do with 4s, 4p, and 4d being filled, leaving 5s and 5p electrons.

[Cooper Baddley 1F]

I think it comes from the element's unfilled outer orbital as it only has 5s2 and 5p3 which in total adds up to 5 valence electrons.

[Suraj Doshi 2G]

The five valence electrons come from the breakdown:

3e from the p-orbital and then 2e from the s-orbital.

I believe that for antimony the electrons are pulled from the s orbital too as they are further away from the nucleus.

[William Francis 2E]

Antimony (Sb) has an electron configuration of [Kr] 4d10 5s2 5p3. Valence electrons are the electrons in an atoms outermost shell. In this case, the fifth shell of electrons is the outermost and it contains 2 electrons in the s subshell and 3 in the p subshell. So, in total, it has 5 valence electrons.

[Daniel Martinez 1k]

Sb has the electron configuration [Kr] 4d^10 5s^2 5p^3.
Since the 4th shell is completely filled, we only focus on the electrons from the fifth shell. With that being said, we only have 5 valence electrons in the 5th shell (2 e- from s-shell & 3 e- from p-shell).

[Jingyao Chen 4H]

The electrons in 5s and 5p are in a high energy level than 4d. Therefore, valence electrons, and the electrons that gets stepped away first are in 5s and 5p.