Question

Which of the following electronic configurations is not possible: Li-3: 152 251 O N-7: 1s22s22p3 Ne-10: 152 2p6 352 O K-19: 152 252 2p6 3s2 3p6 4s1 O All of the above configurations are possible.

Answer 1

Ne-10: 1s2 2p6 3s2 electronic configuration is not possible.

Explanation:

It is not possible because according to Aufbau principles the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels.

Here after 1s orbital is filled the next higher energy orbital is 2s not 2p. So the filling of the electrons in this manner is not possible.

The correct electronic configuration is

Ne-10: 1s2 2s2 2p6.