Question

write the electronic configuration for Cr(24) and Cu(29)....

help me my frnds...

Answer 1

The Electronic configuration of Cr and Cu are given below ⇒

1. Cr = 24 = 1s² 2s² 2p⁶ 3s² 4p⁶ 4s¹ 3d⁵

2. Cu = 29 = 1s² 2s² 2p⁶ 3s² 4p⁶ 4s¹ 3d¹⁰

These electronic configuration are exceptional because electrons entered in 3-d orbitals without filling the 4s orbitals complete.

Reason for the Exceptions ⇒ It is said that d orbitals can be stable if it is half filled or full filled.

Thus, In the given case, electrons reaches near the half filled and full filled thus due to the attraction one electrons from the s orbitals came in d orbitals.

Hope it helps.

Answer 2

Answer:

because half filled or full filledsubshell is more stable so electron from 4s excite and move to 3d subshell to make it stable