PARTICULATE NATURE OF MATTER

CONTENT

1. Molecules
2. Definition of Molecules
3. Structure, Nature and Size of Molecules
4. Some Ideas about Molecular Size
5. Estimating the Size of a Molecule
6. States of Matter
7. The Kinetic Molecular Theory of Matter
8. Fundamental Assumptions of the Kinetic Molecular Theory
9. Basic Assumptions of the Kinetic Theory of Gases
10. Characteristics of the Three States of Matter
11. Crystalline and Amorphous Substances
12. Crystals
13. Non-Crystalline and Amorphous Solids
14. Differences between Amorphous and Crystalline Substances

Molecules

Definition of Molecules

A molecule is the smallest particle of a substance which can have a separate existence and still retain the properties of that substance.

Structure, Nature and Size of Molecules

(i) Most substances cannot exist by themselves as individual atoms, rather they combine their atoms with themselves or with other atoms to form molecules. Thus a molecule may be made up of similar atoms of the same element or different atoms of two or more elements.