JEE Main 2023 — S Block Elements Question with Solution

${\mathrm{BeCl}}_2$ forms a polymeric structure in the solid state due to coordination bonds formed by chlorine donating a lone pair of electrons to the beryllium atoms.

In the vapour phase at moderate temperatures, ${\mathrm{BeCl}}_2$ exists as a dimer, forming a bridge structure with two chlorine atoms connected to two beryllium atoms.

At very high temperatures, ${\mathrm{BeCl}}_2$ exists as monomers due to the high kinetic energy of the molecules, which overcomes the dimerisation tendency.