Question

Which of the following does not have a diagonal relationship between Beryllium and Aluminium.
A) Both \[BeO\] and $A{l_2}{O_3}$ are amphoteric in nature.
B) Bothe beryllium and aluminium form polymeric covalent hydrides.
C) Both beryllium and aluminium form nitrides from nitrogen which evolve $N{H_3}$ with water.
D) Both metal carbonates are highly stable.

Answer 1

Hint: We know that a diagonal relationship is seen in the diagonally adjacent elements of the second and third period. These elements show similar physical and chemical properties. Beryllium is present in the second period and aluminium is present in the third period of the periodic table and are placed diagonally and hence they show diagonal relationship.

Complete step-by-step answer:
The carbonates formed by both beryllium and aluminium are unstable as we know that cations with high ionic potential have large power of ionization. Also, the size of the metal cation is very small as compared to the carbonate anion which tends to form covalent bonds as the lattice energy will decrease. So, we know that there will be less ionization which will therefore make the carbonates less stable. Also, the thermal stability and the ionic character decreases from $Be$ to $Ba$ which means that beryllium will have the least stability.

Therefore, the correct answer is option D.

Note: Diagonal relationships of beryllium and aluminium are as follows:
i) Both of them occur as minerals.
ii) Both of them do not react with atmospheric nitrogen and oxygen.
iii) Both of them do not react with water at high temperature
iv) They do not liberate hydrogen from reacting with acid.