Question

What is the electronic configuration of $C{{l}^{-}}$?

Answer 1

Hint: Before answering this question, we should first know that In an element, the electrons are distributed in their atomic orbitals i.e Electronic configuration. It follows a certain procedure or notation where all-electron-containing atomic subshells (the number that is in the superscript) are put in a pattern and sequence. The atomic number of Chlorine (I) is 17.

Complete answer:
The ground state atom is when the lowering of energy of electrons is not possible by transferring the electrons to the different orbitals. This configuration is the most stable one. The electrons in an atom are arranged in a pattern/sequence in shells.
The shells are represented by integer numbers 1,2,3,4 and so on. They are arranged in increasing order of the energy and are called principal quantum numbers.
n= 1,2,3..
The maximum number of electrons that a shell can hold are:
(K) n = 1 is 2
(L) n = 2 is 8
(M) n = 3 is 18
(N) n = 4 is 32
The azimuthal quantum number refers to the subshells in a shell that are represented by s,p,d,f… $\ell$=0 to (n-1), the value of $\ell$ can be equal to or greater than 0 and less than or equal to n-1.
The maximum number of electrons in a subshell is given by 2(2$\ell$+1).
So, the maximum number of electrons in the subshell
($\ell$= 0) s is 2
($\ell$= 1) p is 6
($\ell$= 2) d is 10
 ($\ell$= 3) f is 14
So, the ground-state electron configuration of a neutral atom of chlorine:
$^{17}Cl=1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{5}}$
The chloride ion ($C{{l}^{-}}$) has a charge of -1 that means it gained 1 electron in the outermost orbital. So, now the number of electrons present is 18.
$^{18}C{{l}^{-}}=1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}$

Note:
The problem we face while writing the electronic configuration is that they are very lengthy and often make our work more, In this, we use abbreviations or condensed notations in place of the standard notations. The abbreviated notation is known as shorthand configuration. In this, the sequence of filled subshells that is relative to the electronic configuration of a noble gas is replaced by the symbol of that noble gas. The symbol of noble gas is written in square brackets.