Question

an atom has 2 electrons in K cell 8 electrons in l cell and 6 electrons in M shell the number of valence electron present in the atom is​

Answer 1

K L M
2 8 8
Thus, atomic number of the element will be 18.
And electronic configuration of the element can be given as:
1s
2
2s
2
2p
6
3s
2
3p
6

Thus, total number of s electron is 6.