🔬 MCAT Exam Prep

What is the correct electron configuration of iron (Fe, Z=26)?

A [Ar] 3d6 4s2
B [Ar] 3d8
C [Ar] 4s2 4p6
D [Ar] 3d5 4s3

✓ Correct Answer: Option A

Iron: [Ar] 3d6 4s2. The 4s orbital fills before 3d, and iron has 8 electrons beyond the Ar core distributed as 3d6 4s2.

Related MCAT Exam Prep Questions