Question

Which of the following is not a similarity of beryllium with aluminium ?

• A. It becomes passive when treated with conc. $HNO_3$
• B. It forms polymeric covalent hydrides
• C. Carbonate of $Be$ is extremely stable
• D. Salts of $Be$ do not impart colour to the flame

Answer 1

Answer: (C)

Carbonate of $Be$ is extremely stable

Answer 2

Beryllium shows resemblance with its diagonally opposite element aluminium. Points of similarity are- Both metals have a tendency to form covalent bonds. Eg; Chlorides of both are being covalent are being soluble in organic solvents. Both $BeCl _{2}$ and $AlCl _{3}$ act as Lewis acids and are used as Friedal Kraft's catalyst. These two elements have the same electronegativity and polarizing power i.e. charge per radius ration of their ions are very similar. They form polymeric covalent hydrides. They become passive when treated with conc. $HNO _{3}$ Salts of Be do not impart colour to the flame. But, the stability of Carbonate of Be is not similar to carbonate of Al.