Question

Find the wrong electronic configurations from the following. What is wrong in these? 

a. 1s² ,2s² ,2p⁶ ,3s² ,3p⁶ ,3d⁹ ,4s²

b. 1s²

c. 1s² , 2s¹ , 2p⁶

 d. 1s² , 2s² , 2p⁶ , 3s² , 3p²

Answer 1

(a) and (c) are wrong electronic con figurations.

In (a) one electron from 4s is to be transferred to 3d since completely filled configurations are more stable. So the correct electronic configuration is 1s² , 2s² , 2p⁶ , 3s² , 3p⁶ , 3d¹⁰ , 4s¹ 

In (c) electrons are filled in 2p only after filling electrons in 2s.