Question

What is the electron configuration for a nitrogen $ 3^- $ ?

Answer 1

Hint: To solve the given question, the concepts to be cleared are about Quantum number, shells, sub-shells, orbitals, Pauli Exclusion Principle, Aufbau Rule, and P fund's Rule.
Quantum number is basically the address of an electron in an atom. Shells are the permitted orbits where an electron revolves with fixed angular momentum. Subshell is a division under the shell that contains orbital or orbitals.

Complete step by step answer:
The formula for nitride ion is $ N^{3-} $ . Here, the total number of electrons in the ion is $ 10 $ .
The four quantum numbers are Principal Quantum Number which denotes the shell, Azimuthal Quantum Number denoting sub-shell, Magnetic Quantum Number, and Spin Magnetic Number.
The sub-shells are s,p,d,f, . . . . . . and so on. They are filled on the basis of energy with $ n+l $ rule.

So, $ N^{3-} $ can be represented as $ 1s^2 2s^2 2p^6 $ .

Additional Information:
1. Pauli’s Exclusion Principle states that any $ 2 $ electron can never have all the same $ 4 $ quantum numbers.
2. The rule explains the filling of electrons according to energy level.
3. P fund’s Rule explains that every orbital with one electron then fills another electron.
4. The magnetic quantum number differentiates orbitals in a given subshell. The l is always less than shell when $ l=0,s;l=1,p;l=2,d;l=3,f; and so on.
5. $ 2 $ Electrons are present in s, $ 6 $ in p, $ 10 $ in d and $ 14 $ in f.

Note:
During the electronic configuration, always make sure to write with inner to outer shells but fill the electron according to energy. The energy of $ 3d $ is more than $ 4s $ but $ 3d $ is written inner to $ 4s $ .