Group the following as linear and non-linear molecules: $H_2O$,$HOCl$,$BeCl_2$,$Cl_2O$.

(N/A) The structures of the given molecules are:
$1$. $H_2O$: Bent (non-linear) due to two lone pairs on the oxygen atom.
$2$. $HOCl$: Bent (non-linear) due to two lone pairs on the oxygen atom.
$3$. $BeCl_2$: Linear due to the absence of lone pairs on the central $Be$ atom.
$4$. $Cl_2O$: Bent (non-linear) due to two lone pairs on the oxygen atom.
Therefore,only $BeCl_2$ is linear and the rest of the molecules ($H_2O$,$HOCl$,$Cl_2O$) are non-linear.