Malleability and ductility of metals can be accounted for due to

The lattice enthalpy of an ionic compound is the enthalpy change when one mole of an ionic compound in its solid state dissociates into its ions in the gaseous state. It is impossible to determine it directly by experiment. Suggest and explain an indirect method to measure the lattice enthalpy of $NaCl_{(s)}$.

Which of the following intermolecular forces are present in solid hydrogen?

The molecule,which is not hydrolysed by water at $25^{\circ} C$ is $......$

Which one of the following substances consists of small discrete molecules?

Which of the following does not exist as an ionic substance in solid state?