This chemistry video tutorial explains the difference between elements, atoms, molecules, and ions. It also explains how to distinguish ionic and molecular compounds also known as covalent compounds. Atoms are electrically neutral and contain equal number of protons and electrons. Ions have a net charge and contain a different number of protons and electrons. Positively charged ions are known as cations and negatively charged ions are known as anions. Atoms and Ions have the same number of neutrons. A molecule is particle consisting of multiple atoms. Pure elements are substances composed of one type of atom where as a compound is made up of different types of atoms. Ionic compounds consist of metals and nonmetals and contain ions with charges. Covalent compounds or molecular compounds usually consist of nonmetals.