Determination of electrical conductivity:
relationship between the electrical conductivity and the type of intermolecular force of attraction existing between the molecules
There are about 5 different types of intermolecular forces. One of those forces is covalent bonding, which is usually found in the bonding of metals.
Metals include elements such as, iron, copper, chromium, titatium, etc., I'm sure you know what a metal and non-metal is by looking at your periodic table.
melting is breaking the bonds in the crystals. Thus, what does that mean? The stronger the bonds are, the harder to break and therefore the higher the melting point.