What is the ground-state electron configuration of a neutral Manganese (Mn) atom (Z = 25)?
[Ar] 4s² 4d⁵
[Ar] 3d⁵ 4s²
[Ar] 3d⁶ 4s¹
[Ar] 4s² 4p⁵
📝 Detailed explanation
According to the Aufbau principle, the 4s orbital is filled before the 3d orbital. For Mn (25 electrons), the configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵, which is abbreviated as [Ar] 3d⁵ 4s².