Question

What is the electron configuration of ${\mathrm{F}}^{-}$?

Answer 1

Fluorine(F):

• Fluorine is a p-block element having atomic number 9.
• Fluorine belongs to group 17 which is known as halogens.

Electronic configuration of Group 17

• The elements of group 17 have seven electrons in their outermost shell.
• So, the valence electronic configuration of group 17 is $\text{n}{\mathrm{s}}^2\text{n}{\mathrm{p}}^5$.

Electronic configuration of ${\mathrm{F}}^{-}$

• The electronic configuration of fluorine is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^5$.
• ${\mathrm{F}}^{-}$ is formed by gaining one electron by fluorine atom.
• So, the electronic configuration of ${\mathrm{F}}^{-}$ is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^6$.