Answer: Be is above H in activity series; H 2 is discharged preferentially at the cathode.
- A Be is above H in activity series; H<sub>2</sub> is discharged preferentially at the cathode
- B Beryllium's melting point is generally too high for aqueous electrolysis as widely reported
- C Beryllium chloride's covalent bonding prevents it from dissolving in water
- D Beryllium is a radioactive element unsuitable for aqueous processing in standard practice
Correct answer: A. Be is above H in activity series; H<sub>2</sub> is discharged preferentially at the cathode
Explanation: Be<sup>2+</sup> has very high hydration enthalpy and is reduced above the reduction potential of water, so H<sub>2</sub> is released instead at the cathode in aqueous solution.
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.