Molecular (or covalent)compounds are made of nonmetals.Atoms of different elements join together in definite proportions to form molecules of compounds. Examples— water, ammonia, carbon dioxide.
Ionic compounds are made of metals and nonmetals. Compounds composed of metals and non-metals contain charged species. The charged species are known as ions. An ion is a charged particle and can be negatively or positively charged. A negatively charged ion is called an anion and the positively charged ion is called cation. Examples— sodium chloride, calcium oxide.