Question

Outer electronic configuration of `K, Cu`, and `Cr` are, respectively,
A. `4s^(1),3d^(10), 3d^(5)`
B. `4s^(1), 3d^(10), 3d^(4)`
C. `4s^(1), 3d^(9), 3d^(4)`
D. `4s^(1), 3d^(9), 3d^(4)`

Answer 1

Correct Answer - A
`K(Z = 19):1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(1)`or `[Ar] 4s^(1)`
`Cr(Z = 24):1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3s^(5)4s^(1)`or `[Ar]3s^(5)4s^(1)`
`Cu(Z = 29):1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3s^(10)4s^(1)`or `[Ar] 3d^(10)4s^(1)`