Exercise 2A. 17a

[SamanyaCMuyunga1K]

Predict the number of valence electrons present for each of the following ions: Mn^4+.

I know that the answer is 3, but how is this the answer?
When I tried to find the answer, I first found the electron configuration for Mn, . Then I removed 2 electrons from the 4s orbital and 2 electrons from the 3d orbital, which means the electron configuration is . So then to complete the d orbital, wouldn't it need 7 more electrons?

[Madilyn Schindler 3E]

The valence electrons are just the number of electrons that are in the outmost shell. Since 3d is the only orbital in the outmost shell, 3, and there are 3 electrons in it, the number of valence electrons is 3. Hope that helps!

[Brendan Duong 1I]

Predict the number of valence electrons present for each of the following ions: Mn^4+.

I know that the answer is 3, but how is this the answer?
When I tried to find the answer, I first found the electron configuration for Mn, . Then I removed 2 electrons from the 4s orbital and 2 electrons from the 3d orbital, which means the electron configuration is . So then to complete the d orbital, wouldn't it need 7 more electrons?

Valence electrons aren't the amount of electrons needed to complete the orbital, its the amount of electrons on the outermost shell. You said it yourself, the electron config will be [Ar]3d^3, so there would be just the 3 valence electrons present