Question

summarise the rules for writing of distribution of electrons in various shells for the first eighteen element​

Answer 1

1) The maximum number of electrons which can be accommodated in any energy level of the atom of an element is given by 2 n² (  n => the number of that energy level ).

• the maximum number of electrons which can be accommodated in 1st energy level (n=1)

K shell is 2 × (1)² = 2 × 1 = 2

• the maximum number of electrons which can be accommodated in 2nd energy level (n=2)

L shell is 2× (2)² = 2 × 4 = 8.

• the maximum number of electrons which can be accommodated in 3rd energy level (n=3)

M shell is 2 × (3)² = 2 × 9 = 18

• the maximum number of electrons which can be accommodated in 4th energy level (n=4)

N shell is 2 × (4)² = 2 × 16 = 32.

2) The outermost shell of an atom cannot accommodate more than 8 electrons, even if it has the capacity to accommodate more electrons

( however , the outermost shell of an atom is the first shell or K shell , then it cannot accommodate more than 2 electrons).

3) The electrons is an atom do not occupy a new shell unless all the inner shells are completely filled with electrons.

This means that first of all the electrons fill K shell , then L shell , then M shell ETC....