JEE Main · 2022 · 25 Jul 2022 · Shift 2 · s-Block Elements

In Group 2 (alkaline earth metals), density generally increases down the group due to increasing atomic mass. However, there's an anomaly:

Density decreases from Be to Ca (due to increasing atomic size dominating over mass increase), then increases again from Ca onwards (as the mass increase becomes more significant).

The correct order is: $\mathrm{Sr}>\mathrm{Be}>\mathrm{Mg}>\mathrm{Ca}$

Sr has the highest density, followed by Be (which is unusually dense for its position), then Mg, with Ca having the lowest density in this series.