The maximum number of electrons that can be accommodated in a shell depends on the formula ____.

Question

Question

This question was previously asked in

RRB ALP CBT I 21 Aug 2018 Shift 1 Official Paper

Answer 1

The correct answer is 2n².

Key Points

Pauli's exclusion principle states that no two electrons in an atom can have identical values for all four quantum numbers(n,l, ml and ms).
For example, subshell 1s can accommodate only 2 electrons.
For 1s orbital- n=1, l=0, ml= 0 and ms = + or –
According to this principle, the number of electrons that can be accommodated in a shell is given by 2n2.
For example, K shell contains only one subshell 1s, so the maximum number of electrons occupied in K shell is 2.
The maximum number of electrons that can be accommodated in a shell is indicated by the formula 2n2.
Number of electrons in one shell =2n2
Where n is the shell number. So the second orbital would be 2 (22) = 8

Principle energy level (n)	Subshells	Number of orbitals per subshell	Maximum number of electrons in the shell(2n2)
1	s	1	2
2	s	1	8
2	p	3	8
3	s	1	18
	p	3
	d	5
4	s	1	32
	p	3
	d	5
	f	7