Question

Which of the following is not a similarity of beryllium with aluminium?
A.It becomes passive when treated with conc. $HN{O_3}$.
B.It forms polymeric covalent hydrides.
D.Carbonate of Be is extremely stable.
E.Salts of Be do not impart colour to the flame.

Answer 1

Hint: Try to recall that beryllium shows resemblance with its diagonally opposite element aluminium due to similar charge/radius ratio. Now, by using this you can easily find the correct option from the given ones.

Complete step by step solution:
It is known to you that both beryllium and aluminium have the same electronegativity and have similar properties. Some of the similarities are as follows:
Both metals have a tendency to form covalent compounds, e.g. the chlorides of both being covalent are soluble in organic solvents.
Both beryllium and aluminium are resistant to the action of acids like nitric acid due to formation of passive layers of oxide on their surface.
Both beryllium and aluminium carbonates are unstable in normal conditions.
Also, salts of both beryllium and aluminium do not impart colour to the flame.
Both aluminium and beryllium hydrides form covalent polymeric hydrides.
The oxides of both aluminium and beryllium are hard, high melting insoluble solids.
The oxides and hydroxides of both beryllium and aluminium are amphoteric and dissolved in sodium hydroxide solution as well as in hydrochloric acid.
Therefore, from above points we can easily conclude that option C is the correct option to the given question.

Note:
It should be remembered to you that because of similar polarising power both beryllium and aluminium form complexes.
Also, you should remember that both metals dissolve in strong alkalies to form soluble complexes and carbides of both metals react with water liberating methane gas.