Question

With the help of Pauli's exclusion principle,
taking electronic configuration of lithium
atom as example, show that there can be maxi-
mum of two electrons in an orbital of an atom.​

Answer 1

Answer:

Lithium-Li:1S2 2S1

according to Pauli's exclusion one orbital have 2 electron must .

No of electron present in Li is 3 so 1S orbital have 2 electron & the rest 1 electron is in 2S orbital.

Answer 2

Total number of electrons in lithium = 3

According to paulis exclusion principle states that no two electrons can have the same set if 4 quantum numbers.In other words ,only two electrons may exist in the same orbital and these electrons must have opposite spin.

Therefore E. C of lithium according to This principle = $1s^{2} 2s^{1}$