Write a note on the anomalous behaviour of beryllium.

Explanation

Anomalous characters of Be:-
As was already discussed in the earlier sections, the first element shows some differences from the properties of the other elements in the group. Be differs from the other alkaline earth metals. Because of its small size and high electronegativity Be differs from the other elements in the following aspects:
(i) Be compounds are predominantly covalent due to its high polarizing power and its salts are readily hydrolyzed.
(ii) Be is not easily affected by dry air and does not decompose water at ordinary temperature.
(ii) Be is an amphoteric metal. It dissolves in alkali solutions forming beryilates.
(iv) Be `SO_4` is soluble in water whereas the sulphates of Ca,Sr and Ba are not soluble.
(v) Be and its salts do not respond to flame test while Ca, Sr and Ba give characteristic flame colours.
(vi) Be forms many complexes while the heavier elements do not show a great tendency to form complexes.
(vii) Be has a maximum covalency of 4 while other can have a maximum covalency of 6.