Question

State the electronic configuration for Magnesium [p=$12$, n=$12$].

• A. $2,8,0$
• B. $2,8,1$
• C. $2,8,2$
• D. $2,8,3$

Answer 1

The correct option is C $2,8,2$

As we know, atomic no. is the total no of proton present in nucleus of an atom and atomic mass no is the total no of proton and neutron.
So $Mg$ have atomic no. $12$ and mass no. $12+12=24$. K shell can accommodate a maximum of $2$ electrons, L shell can accommodate a maximum of $8$ electrons. Remaining electrons will be accommodated in M shell. So the configuration is $2,8,2$.