Consider the elements , and . How many of these elements have an atomic radius strictly larger than — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

Based on group and period trends: In Group 13, the order is $B < Ga \approx Al < In < Tl$. So $In$ and $Tl$ are larger than $Al$. Across period 3, the radius decreases: $Mg > Al > P > S > Cl$. Therefore, $Mg$ is larger than $Al$. Elements larger than $Al$ are $In, Tl,$ and $Mg$. Total = 3.