This document summarizes key concepts about atoms, molecules, and chemical bonds. It defines atoms as the smallest unit of an element, consisting of a nucleus with protons and neutrons surrounded by electrons. Molecules are formed when two or more atoms bond together, such as through covalent bonds where atoms share electrons. The document also outlines Dalton's atomic theory and the laws of chemical combination, including the law of conservation of mass and the law of constant proportions.

1. Atoms & Molecules

2. Laws of chemical combination

3. 1. Law of conservation of mass Law of conservation of mass states that mass can neither be created nor be destroyed.

4. 2. Law of constant proportions A pure chemical compound always contains same elements combined together in the same definite proportion by weight.

10. Symbols of atoms of different elements

11. The Electron Cloud

13. Molecules

16. Chemical Bonds

17. Types of Bond

18. Covalent Bond