How to mention the atom notation ? Give example

Explanation

In the representation of atom element X is placed with elements X at left side superscript mass A os placed and at left side at subscript atomic number Z is placed.
X= electron A = mass Z= atomic no
Example `e.g_(11)^(23)` sodium (Na ) atomic number (Z ) is 11 and atomic mass (A ) is 23
So Z= 11 , A =23