Question

Discuss the unusual behaviour of lithium. Lithium shows
greater resemblance with magnesium than with other alkali metals. Explain
with reasons.​

Answer 1

The unusual behaviour of lithium is as follows:

.Lithium is harder than other metals of the respective group.

.It has higher Melting and boiling point than other metal

.It is least reactive.

.It is strongestreducing agent.

.Unlike other metals LiCl is deliquescent and exist as LiCl.2H2

.Lithium does not form ethynide on reacting with Ethyne.

Resemblance of lithium with magnesium and other alkali metals:

.Both Li and Mg are harder and lighter than other elements in their groups.

.Both form ionic nitrides Li3N and Mg3N2 by heating in an atmosphere of nitrogen. Li resembles Mg due to similar atomic radii and ionic radii.