JEE Main 2025 Jan 28 Shift 1, Chemistry Q1: Periodicity In Atomic Properties

Atomic radius increases down a group and decreases across a period. Beryllium lies above magnesium in Group 2, so $\text{Be}<\text{Mg}$, not $\text{Be}>\text{Mg}$.

The correct ordering is $\text{Mg}>\text{Al}>\text{Si}$, with Be smaller than Mg. Option (3) therefore lists an incorrect order, while the other three orderings are consistent with periodic trends.

$\therefore$ Option (3) is the incorrect order.