$\ \ \ \ \ \text{Cl}-\text{Be}-\text{Cl} \\\ \ \ \ \ \ \text{Structure of}\\\ \text{BeCl in gaseous state}$
In solid state, it has a polymeric structure with chlorine bridges as follows.

Two Cl-atoms are listed to be atom by two coordination bonns and two by covalent bonds. For these bonds to be formed, Be in the excited state with the configuration
$\text{1s}^2\ \text{2s}^1\ 2\text{p}_\text{x}^1\ 2\text{p}^0_\text{y}\ 2\text{p}_\text{z}^0$ undergoes sp3 hybridisation. Two half-filled hybrid orbitals will form normal covalent bonds with two Cl-atom. The other two Cl-atoms are coordinated to Be-atom by donating electron pairs into the empty hybrid orbtitals.Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
$\begin{matrix}\Delta \text{H}^{\circ}_{f} & -919 \text{kJ mol}^{-1} & 0 & -1577 \text{kJ} \text{ K}^{-1} \text{mol}^{-1} \ \\\text{S}^{\circ}& 273 & 203 & 301 \end{matrix}$
$\Delta\text{U}^\ominus$of combustion of methane is – X kJ mol–1. The value of $\Delta\text{H}^\ominus$ is:
$=\Delta\text{U}^\ominus$
$>\Delta\text{U}^\ominus$
$<\Delta\text{U}^\ominus$
$=0$