Question

write the subshell electronic configuration of noble elements- Ne10,Ar18,Kr36​

Answer 1

Subshell electronic configuration of given elements is as follows:

1. Ne => 1s², 2s², 2p⁶
2. Ar => 1s², 2s², 2p⁶, 3s², 3p⁶
3. Kr => 1s², 2s², 2p⁶, 3s², 3p⁶, 3d¹⁰, 4s², 4p⁶

=> Rules for writing electronic configuration:

1) Afbau principal: The subshell with lower energy is filled first completely.

( ofcourse there are some exceptions like Cr and Cu ツ )

2) Hund's rule: Pairing of electrons in a subshell tales place only when all its orbital are singly occupied by electron having parallel spin.

3) Pauli's exclusion principal: No two electrons in an atom can have same set of all four quantum numbers.

or simply, An orbital can accommodate maximum of two electrons with opposite spin.