Sagot :
because of its bonds
Ionic bonds are very strong - a lot of energy is needed to break them. So ionic compounds have high melting and boiling points.
An ionic compound is arranged in a organised lattice structre that allows for the greatest electrostatic attraction between the opposite charged atoms and the lesser electrostatic repulsion between the same atoms, where the atoms are as closely packed as possible. So the amount of energy (in form of heat) needed to break the electrostatic attraction between the atoms, so this means that ionic compounds have very high melting points.