Question

why does lithium differ from its own family members​

Answer 1

Answer:

Lithium is hard, has high electronagitivity, high ionisation potential, high melting as well as boiling point, lithium hydride are stablest hydrides, it is the only alkali metal which can react with nitrogen to form nitride, due to its small size it forms covalent compounds,it shows diagonal relationship with beryllium.

Answer 2

Answer:

Actually , Among the alkali metals, Lithium has the smallest atomic and ionic size and has the highest polarizing power. Due to this, lithium compounds are covalent.Making it different.

OR

Lithium is hard, has higher electro negativity than others, higher ionization potential, higher melting as well as boiling point, lithium hydride are stable hydrides, it is the only alkali metal which can react with nitrogen to form nitrides, due to its small size it forms compounds with covalent characters.