College

Which of the following is the correct electron configuration for [tex]Fe^{3+}[/tex]?

A. [Ar] 3d[tex]\(^5\)[/tex]
B. [Ar] 4s[tex]\(^2\)[/tex] 3d[tex]\(^3\)[/tex]
C. [Ar] 4s[tex]\(^2\)[/tex] 4p[tex]\(^3\)[/tex]
D. [Ar] 4s[tex]\(^2\)[/tex] 3d[tex]\(^9\)[/tex]

Answer :

Sure! Let's work through the problem step-by-step to find the correct electron configuration for [tex]\( \text{Fe}^{3+} \)[/tex].

1. Identify the Atomic Number of Iron (Fe):
- Iron (Fe) has an atomic number of 26. This means a neutral iron atom has 26 electrons.

2. Write the Electron Configuration for Neutral Iron (Fe):
- The electron configuration of a neutral iron atom is: [tex]\([ \text{Ar} ] \, 3d^6 \, 4s^2\)[/tex].

3. Form the [tex]\( \text{Fe}^{3+} \)[/tex] Ion:
- To form the [tex]\( \text{Fe}^{3+} \)[/tex] ion, we need to remove 3 electrons from the neutral iron atom.

4. Remove Electrons:
- Electrons are removed from the highest energy level first. For iron, the 4s orbital has a slightly higher energy than the 3d orbital. Therefore:
- Remove 2 electrons from the 4s subshell: [tex]\([ \text{Ar} ] \, 3d^6 \, 4s^2 \rightarrow [ \text{Ar} ] \, 3d^6\)[/tex].
- Remove 1 more electron from the 3d subshell: [tex]\([ \text{Ar} ] \, 3d^6 \rightarrow [ \text{Ar} ] \, 3d^5\)[/tex].

5. Final Electron Configuration for [tex]\( \text{Fe}^{3+} \)[/tex] Ion:
- The electron configuration of the [tex]\( \text{Fe}^{3+} \)[/tex] ion is: [tex]\([ \text{Ar} ] \, 3d^5\)[/tex].

Among the options provided, the correct configuration ([tex]\([ \text{Ar} ] \, 3d^5\)[/tex]) was not listed, but this would be the correct electron configuration for [tex]\( \text{Fe}^{3+} \)[/tex].