The solid phosphorus pentachloride exists as:

The hydration energies of $K^{+}$ and $Cl^{-}$ are $-x$ and $-y$ $kJ / mol$ respectively. If the lattice energy of $KCl$ is $-z$ $kJ / mol$,then the heat of solution of $KCl$ is $:$

Explain the Born-Haber Cycle.

Which of the following forces is effective between noble gas atoms?

The solid $NaCl$ is a bad conductor of electricity since:

Diamond is covalent,yet it has a high melting point. Why?