Question

Which of the following is not correct for electronic distribution
in the ground state ?
(a) Co [Ar]
(b) Ni [Ar]
(c) Cu [Ar]
(d) All of the above

Answer 1

(c)

• Correct configuration should be 1s2 2s2 2p6 3s2 3p6 3d10 4s1 for the copper which has atomic number 29 (.29Cu).
• Due to extra stability of full flled orbital of d-subshell, the last electron enter into d-orbital instead of s-orbtial.