Question

If in an atom M shell has 2 electrons determine the atomic no. of atom. Identify the element and give its symbol.

Answer 1

If M shell has 2 electrons then value of all shells like K and L would be:

K=2

L=8

M=2

so electronic configuration is: 2, 8, 2 so the atomic number of atom would be 12 and the element would be Magnesium and its symbol is Mg.