Bohr-Rutherford diagram help??

Question

Im trying to draw Bohr-Rutherford diagram of sodium and its atomic number is 11 and atomic mass is 23. And theres supposed to be 12 electrons on its shell so I draw the diagram but when I check the answer theres 11 electrons drawn not 12. Don't you get the electrons when you mass number - atomic number = electrons.

Answer 1

no, you just use the atomic number.
so it is 11.
for the inner shell, you draw two, [cause thats as manay as it holds] for the next one you draw eight, [cause thats as many as it holds] and then for the third shell, you will draw just one of the circles!

Answer 2

11 proton
12 neutron

11 electons
-2 on first shell
-8 one second shell
-1 on third shell