Anomalous Behaviour of Beryllium - Practice Questions & MCQ

Berylium differs from rest of the alkaline earth metals on account of its small atomic size, high electronegativity and a slight difference in electronic configuration. Be²⁺ is very small. It exerts a high polarising effect on any anion associated with it. On account of this, beryllium compounds show covalent character. Its compounds have low melting points and are soluble in organic solvents. These are hydrolysed in water.

The main points of difference are given below:

• It is the hardest of all alkaline earth metals.
• The melting and boiling points of the beryllium are the highest.
• It is not affected by the atmosphere.
• It does not decompose water.
• It has the tendency to form covalent compounds
• It does not react directly with hydrogen.
• It dissolves in alkalies with the evolution of hydrogen.
• It does not liberate hydrogen from acids readily.
• Its oxide is amphoteric in nature.
• Its hydroxide is amphoteric in nature.
• Its carbide on hydrolysis evolves methane.
• Its carbonate is not stable towards heat.
• Its sulphate is soluble in water.
• BeCl₂ is a covalent compound.
• It has a strong tendency to form complex compounds.
• It has a tendency to form alloys.