---
title: "An aqueous solution contains iron(II) sulfate, which dissociates to form  \\(\\text{Fe}^{2+}\\) ions. Which of the following identifies the ground-state electron configuration of the \\(\\text{Fe}^{2+}\\) ion and provides the correct justification?"
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url: "https://nerd-notes.com/ubq/119603/"
date_modified: "2026-08-21T08:11:40+00:00"
---

# An aqueous solution contains iron(II) sulfate, which dissociates to form 
\(\text{Fe}^{2+}\) ions. Which of the following identifies the ground-state electron configuration of the \(\text{Fe}^{2+}\) ion and provides the correct justification?

An aqueous solution contains iron(II) sulfate, which dissociates to form 
\(\text{Fe}^{2+}\) ions. Which of the following identifies the ground-state electron configuration of the \(\text{Fe}^{2+}\) ion and provides the correct justification?

- **A.** \([\text{Ar}]\, 3d^6\), because electrons occupying the subshell with the highest principal quantum number (\(n = 4\)) are removed first during ionization.
- **B.** \([\text{Ar}]\, 4s^2\, 3d^4\), because electrons are removed from the subshell that is filled last according to the Aufbau principle.
- **C.** \([\text{Ar}]\, 3d^6\), because paired electrons in the \(3d\) subshell experience greater electron-electron repulsions than \(4s\) electrons and are lost first.
- **D.** \([\text{Ar}]\, 4s^1\, 3d^5\), because achieving a half-filled \(3d\) subshell maximizes stability and produces the lowest possible energy state.

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