The electronic configuration $1s^2,2s^2p^6,3s^13p^1$ correctly describes :

Question

$\begin{array}{1 1}(a)\;Ground\;state \;of\;Na\\(b)\;Ground\;state\;of\;Si^+\\(c)\;Excited\;state\;of\;Mg\\(d)\;Excited\;state\;of\;Al^{3+}\end{array}$