How do ionic compounds differ from covalent compounds?
Both of the different types of bonds differ in the way in which how they bond and their properties.
Covalent molecules are two non-metal atoms that share their valence electrons to complete their outer shell. For example, Hydrochloric Acid (HCl). Generally, Covalent molecules also have different properties to ionic compounds like low melting point and boiling point, not soluble in water and do not conduct in its molten state, pure state or in water.
Ionic compounds occur between a non-metal and a metal where positive and negative ions occupying alternate positions in a regular lattice. The positive ions are metal ions that have lost electrons and the negative ions are non-metals that have gained electrons. For example, Sodium Chloride (NaCl). Generally, Ionic compounds have different properties to covalent molecules like high melting point and boiling point, soluble in water and not conductive in its pure state but conductive in its molten state and when mixed in water.