Answer: Covalent compounds (high charge density, small size).
- A Covalent compounds (high charge density, small size)
- B Mainly ionic compounds like the rest of Group 2 typically does
- C Predominantly metallic compounds rather than discrete molecules
- D Stable compounds directly with noble gas elements
Correct answer: A. Covalent compounds (high charge density, small size)
Explanation: Be has the smallest ionic radius and highest charge density in Group 2, causing it to form covalent bonds and behave more like aluminium (diagonal relationship).
Each s-block metal ion emits a characteristic flame colour because heating excites electrons to higher energy levels; light is emitted as they fall back, with the colour determined by the specific energy gap.
Concept context
Group 1 (alkali metals) and Group 2 (alkaline earth metals). Learn their reactions with water and air, important compounds like NaOH, Na₂CO₃, and CaCO₃, and anomalous behaviour of lithium and beryllium.