Question

Beryllium and aluminium exhibit many properties which are similar but the two elements differ in ___________.

• A. forming covalent halides
• B. forming polymeric halides
• C. exhibiting maximum covalency in compounds
• D. exhibiting amphoteric nature in their oxides

Answer 1

The correct option is C exhibiting maximum covalency in compounds

Both aluminium and beryllium oxides are amphoteric in nature. Both the elements can form covalent bonds. Both aluminium and beryllium hydrides are electron deficient and so, they need to form dative bonds with neighboring molecules. In the end, they form a long polymer held in place by dative bonds. However, beryllium does not exhibit coordination number more than four as it has four orbitals in the valence shell. The other members of this group has coordination number of $6$.
Hence, maximum covalency exhibted by aluminium compounds is greater than that of beryllium.