If K and L shells of an atom are full, then what would be the total number of electrons in the atom?

Q.:- If K and L shells of an atom are full, then what would be the total number of electrons in the atom?

 

Answer:-

The maximum number of electrons present in a shell = 2n2

Where n = shell number
Value of n for K shell = 1
Therefore, Maximum number of electrons in K shell = 2n2 = 2(1) = 2
Value of n for L shell = 2
Therefore, Maximum number of electrons in L shell = 2(2)2 = 8
Thus, total no. of electrons = 2 + 8 = 10