PECULIAR BEHAVIOUR OF BERYLLUM

PECULIAR BEHAVIOUR OF BeRYLLUM

Be shows different behaviour than its family members

It is due to following reasons

•      Size of Be is very small, and

•      Electronegativity of Be is quite high than its family members.

1.                  Be is as hard as iron. It is quite hard to scratch glass, while other alkaline earth metals are softer than Be but still harder than alkali metals.

2.                  Melting points and boiling points of Be are higher than other alkaline earth metals

3.                  In principal all group IIA metals can reduce water. But Be forms insoluble oxide coating over the surface that protects it from further attack.

4.                  Be is more resistant to complete oxidation as compare to its family members, because of its BeO coating.

5.                  Only Be reacts with alkalies to give H₂ gas while other alkaline earth metals do not give this reaction.

                                           Be + 2NaOH                         Na₂BeO₂ + H₂

                                                                               Sodium beryllate

6.                  Be mostly forms covalent compounds while other alklaline earth metals form ionic compounds

7.                  Oxides and hydroxides of Be are amphoteric while other alkaline earth metals form basic oxides and hydroxides