Which element exhibits an electron configuration that defies the Aufbau principle by having a half-filled d-orbital instead of a filled s-orbital?
Q1. Which element exhibits an electron configuration that defies the Aufbau principle by having a half-filled d-orbital instead of a filled s-orbital?
Answer: Chromium
Explanation: Chromium's [Ar] 3d⁵4s¹ configuration shows half-filled d-orbital stability. Option A has a similar anomaly but with 3d¹⁰4s¹.