Which of the following are the correct reasons for anomalous bhaviour of lithium?
(a) Exceptionally small size of its atom
(b) Its high polarising power
(c) It has the high degree of hydration
(d) Exceptionally low the enthalpy

Although Li exhibits, the characteristic properties of alkali metals it differs at the same time in many of its properties from alkali metals.
The anomalous behaviour of lithium is due to the extremely small size of lithium and its cation. On account of the small size and high nuclear charge, lithium exerts the greatest polarising effect out of all alkali metals on negative ions.

Answers:

(a) Exceptionally small size of its atom
(b) Its high polarising power