JEE Main 2016 · 10 Apr · Shift 1, Chemistry question 33

The argon configuration belongs to $\ce{K+}$, $\ce{Ca^2+}$, $\ce{Cl-}$ and $\ce{S^2-}$. NaF gives $\ce{Na+}$ and $\ce{F-}$, both with the neon configuration.