JEE Main · 2023 · 01 Feb 2023 · Shift 1 · s-Block Elements

Beryllium oxide is amphoteric, reacting with both acids and alkalis, so the claim that it is purely acidic is wrong. Beryllium carbonate is unstable and readily loses carbon dioxide, so it is stored under an atmosphere of carbon dioxide to suppress this decomposition, which is correct. Beryllium sulphate dissolves readily in water because the very high hydration enthalpy of the small $\mathrm{B}{\mathrm{e}}^{2+}$ ion outweighs its lattice enthalpy, which is correct. Beryllium also shows the familiar anomalous behaviour arising from its small size and high charge density, which is correct. The correct statements are that beryllium carbonate is kept under carbon dioxide, beryllium sulphate is readily soluble, and beryllium shows anomalous behaviour.