We know that a shell can accommodate a maximum of 2n2 electrons because a shell can have a maximum of n2 orbitals depending upon the value of n, i.e n=1 for K shell, n=2 for L shell, n=3 for M shell, n=4 for N shell and so on. According to Lewis, he pictured the atom in terms of a positively charged Kernel (the nucleus plus the inner electrons) and the outer shell that could accommodate a maximum of eight electrons. This means that 2n2=8 => n=2? Means an outer shell can be nothing more than an L shell? I got stuck up here and I am still confused..