Question

Write the electronic configuration of $M{n^{2 + }}$ and $F{e^{2 + }}$.

Answer 1

We are discussing the electronic configuration of some ions mentioned above and learning how to write it by its rules. Electronic Configurations means it is a standard notation used to describe the electronic description of an atom.

Complete step by step answer:
For using Electronic Configuration, Aufbau Principle (Aufbau is a German word for ‘Building-Up) is used which states that electrons occupy orbitals in order of increasing energy. The order of Energy is:
$1s < 2s < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s < 4f < 5d < 6p < 7s < 5f < 6d < 7p$

Orbital: An orbital is a space where the probability of electrons is the highest.
There are $4$ orbitals (s,p,d,f)
s is the orbital that has a maximum $2$ electrons capacity.
p is the orbital that has a maximum $6$ electrons capacity.
d is the orbital that has a maximum $10$ electrons capacity.
f is the orbital that has a maximum $14$ electrons capacity.
According to the Question,
Firstly, we can write the electronic configuration of $Mn$ first its atomic number is 25.
$1{s^2}\,2{s^2}\,2{p^6}\,3{s^2}\,3{p^6}\,4{s^2}\,3{d^5}$
After losing $2$ electrons, it will become $M{n^{2 + }}$.
Now, we can write the electronic configuration of $M{n^{2 + }}$ ion
$1{s^2}\,2{s^2}\,2{p^6}\,3{s^2}\,3{p^6}\,4{s^0}\,3{d^5}$
The electrons can be liberated from lower energy orbital (s Orbital) due to more energy gap between s orbital and p orbital and secondly, half-filled orbital and full filled orbital have higher energies and are mainly stable. So, from stable orbitals electrons cannot be released.
Now, We can write the electronic configuration of $Fe$ first its atomic number is 26.
$1{s^2}\,2{s^2}\,2{p^6}\,3{s^2}\,3{p^6}\,4{s^2}\,3{d^6}$
After losing $2$ electrons, it will become $F{e^{2 + }}$
$1{s^2}\,2{s^2}\,2{p^6}\,3{s^2}\,3{p^6}\,4{s^0}\,3{d^6}$
The electrons can be liberated from lower energy orbital (s Orbital) due to more energy gap between s orbital and p orbital.

Note: Almost all the elements follow the same trend for writing electronic configuration. Sometimes when two sub-shells differ in the energies, an electron from the lower energy moves to higher energy. The orbitals in which the subshell is exactly half-filled or completely filled are more stable because of the symmetrical distribution of electrons.