Magnetic measurements on an octahedral complex of a transition metal ion show that it contains two unpaired electrons. Which of the following d-electron configurations of the metal ion are consistent with this fact?
Select the most complete answer.

Question

Quizplus · Accepted Answer

The presence of two unpaired electrons indicates that the metal ion has a high spin configuration. In other words, the electrons occupy the available orbitals with parallel spins before pairing up. Therefore, we can disregard any configurations that have less than two electrons in the eg set of orbitals. 
Option A only has one electron in the eg set, so it is not consistent. 
Option B has the correct configuration, but it is not the most complete answer because it does not include all possible configurations. 
Option C has too few electrons in the eg set, so it is not consistent.
Option E includes all possible configurations, but it is not a specific answer to the question asked. 
Therefore, the best choice(s) are D because it includes all possible configurations with at least two electrons in the eg set.

Magnetic Measurements on an Octahedral Complex of a Transition Metal