Which of the following represents the ground state electron configuration for the Mn3+ ion? (Atomic number Mn = 25)
A
1s2 2s 2 2p 6 3s 2 3p 6 3d 4
B
1s2 2s 2 2p 6 3s 2 3p 6 3d 5 4s 2
C
1s2 2s 2 2p 6 3s 2 3p 6 3d 2 4s 2
D
1s2 2s 2 2p 6 3s 2 3p 6 3d 8 4s 2
E
1s2 2s 2 2p 6 3s 2 3p 6 3d 3 4s 1
Why the answer is A. I dont understand!!
The ground state is 1s2 2s2 2p6 3s2 3p6 3d5 4s2 = 25
Now you remove the two 4s2 to make Mn^2+, the next electron is in the 3d level so remove one of those to make 3d4 and Mn^3+. If this is not clear, please tell me what is confusing about it or exactly what you think it should be. The majority of students I've had write the ground state as 1s2 2s2 2p6 3s2 3p6 4s2 3d5 then remove 3 of the 3d electrons to make Mn^3+. Yes, the order of filling is 3p6 4s2 3d5 but the 4s shell IS THE OUTSIDE SHELL SO THE 4S ELECTRONS ARE REMOVED FIRST.