Question

An atom of elements 'X' has three orbits around its nucleus .What is its maximum electron holding capacity?

Answer 1

the maximum holding capacity of the atom is :
K shell               L shell                M shell
  2                          8                         8
therefore the answer is 18 electrons in three shell . 
         i hope it helps..................

Answer 2

the maximum holding capacity would be 18. it can be satisfied by the 2n2 formula .