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)

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.