Which of the alkali metal is having least melting point?

Question

Philoid · Accepted Answer

⇒ The size of alkali metal increases as we move down the alkali group.

⇒ Thus as the alkali metal size increases, the binding energies

of their atoms in the crystal lattice decreases. Hence, on moving down the alkali group, the strength of metallic bonding decreases. Because of this, melting point decreases.

⇒ Among the given metals, since the size of Cs is the biggest, therefore, its melting point is the lowest. Thus, option (D) is correct.