Question -
Answer -
Smallerthe size of an ion, the more highly is it hydrated. Among the given alkalimetals, Li is the smallest in size. Also, it has the highest charge density andhighest polarising power. Hence, it attracts water molecules more strongly thanthe other alkali metals. As a result, it forms hydrated salts such as LiCl.2 H2O. The other alkali metalsare larger than Li and have weaker charge densities. Hence, they usually do notform hydrated salts.