Which substance has the highest melting point?

Which of the following shows electrical conduction?

Intermolecular forces are forces of attraction and repulsion between interacting particles that will include :
$A$. dipole-dipole forces $B$. dipole-induced dipole forces $C$. hydrogen bonding $D$. covalent bonding $E$. dispersion forces
Choose the most appropriate answer from the options given below :

The compound,found in nature in gas phase but ionic in solid state is

An aqueous solution of potash alum gives .......

In graphite,electrons are