Key Notes for Basic Chemistry. These notes will provide you overview of the chapters and points to remember. Chemistry are covered and are as follow: UNIT 1: Basic Concept of Chemistry. UNIT 2: Structure of Atom. UNIT 3: Classification of Elements. UNIT 4: Chemical Bonding and Molecular Structure. UNIT 5: States of Matter. UNIT 6: Thermodynamics. UNIT 7: Equilibrium.