Question

Write down the electron distribution of chlorine atom. How many electrons are there in the L shell? (Atomic number of chlorine is $17$).

Answer 1

Electronic configuration:

1. The arrangement of electrons in different atomic orbitals is referred as electronic configuration.
2. It is useful determining the valency of an element and determine the properties of an element

Writing electronic configuration:

Shells:

1. Maximum number of electrons can be accommodated in shell is represented by the formula $2{\mathrm{n}}^2$, where n is the shell number.
2. The value of the shell and the number of electrons present in it is tabulated below

Shell and ‘n’ value	Maximum electrons present in a shell
K shell $\left(\mathrm{n}=1\right)$	$2\times 1^2=2$
L shell $\left(\mathrm{n}=2\right)$	$2\times 2^2=8$
M shell $\left(\mathrm{n}=3\right)$	$2\times 2^3=16$
N shell $\left(\mathrm{n}=4\right)$	$2\times 2^4=32$

Given Case:

• The atomic number of chlorine=$17$
• The electronic distribution of chlorine atoms will be:

1. K shell=$2$ electrons
2. L shell=$8$ electrons
3. M-shell=$7$electron

Hence, $\mathbf{8}$ electrons are there in the L shell