CHEMISTRY COMMUNITY

For part b of this problem, the electron configuration for Mn is [Ar] 4s^2 3d^5 right? The question is asking from which orbital will an electron be removed to form a +1 ion, and the correct answer is from the 4s orbital but can someone explain why its from this orbital and not 3d^5?

An electron will be removed from the 4s orbital because the 4s orbital has a lower energy than 3d. 4s has higher energy when when the 4s state is occupied AND electrons enter the 3d state.