Question

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

Answer 1

The maximum number of electrons that can be occupied in K and L-shells of an atom are 2 and 8 respectively.
Therefore, if K and L-shells of an atom are full,
then the total number of electrons in the atom would be (2 + 8) = 10 electrons.