Which of the following electronic configuration represents ion for transition element .…

Question

Which of the following electronic configuration represents ion for transition element .…

a) [Ar] 4s2 , 3d8

b) [Ar] 4s1, 3d10

c) [Ar] 4s0 , 3d9

d) [Ar] 4s2, 3d0

## I need the solution with detailed steps (why)##

Answer 1

The configuration(s) that represents a transition element is/are...

a) [Ar] 4s2 3d8 which is Ni

b) [Ar] 4s1 3d10 which is Cu

Explanation as to why is easiest explained by elimination:

a) [Ar] 4s2 3d8 obeys the Aufbau principle and is transition b/c it is a d-block element

b) [Ar] 4s1 3d10 is transition b/c it is a d-block element and one of the 4s electrons jumped to fill the 3 d

c) [Ar] 4s0 3d9 cannot exist as it has no electrons in the 4 s orbital

d) [Ar] 4s2 3d0 has no d electrons so cannot be a transition element