Question

The electronic configuration of Cu (at.no. = 29) is

• A. $1s^2,2s^2 2p^6,3s^2 3p^6,4s^2, 3d^9$
• B. $1s^2, 2s^2 2p^6, 3s^2 3p^6 3d^{10}, 4s^1$
• C. $1s^2, 2s^2 2p^6, 3s^2 3p^6, 4s^2 4p^6, 5s^2 5p^1$
• D. $1s^2, 2s^2 2p^6, 3s^2 3p^6, 4s^2 4p^6, 3d^3$

Answer 1

Answer: (B)

$1s^2, 2s^2 2p^6, 3s^2 3p^6 3d^{10}, 4s^1$

Answer 2

The electronic configuration of Cu(29) is an exceptional case due to exchange of energy and symmetrical distribution of electrons in orbital to acquire more stability.

copper has the atomic number 29, its electronic configuration is Cu (29)= 1s² 2s²2p⁶ 3s² 3p⁶ 3d¹º 4s¹. This is because half filled and fully filled shells are more stable, therefore it does not follow hund’s rule.