1. States of Matter and Physical and Chemical Changes 1

2. Chemistry is the study of matter. What is matter? Matter: anything that takes up space (volume) and has a mass. 2

3. Properties of matter: Physical properties : are observable and do not change the chemical composition of the matter. Examples of physical properties: different densities, melting points, boiling points, freezing points, colour, odour (smell) and state of matter (solid, liquid or gas). Chemical properties : are only observable through a chemical reaction, and do change the chemical composition of the matter (new substance produced by destroying the original substances). Ex: burning, rusting, reactivity with water or acid. 3

4. Chemical Properties: A good example of chemical properties is the way compounds or elements combine with each other during chemical reactions 4

5. States of Matter Matter can be found in 3 states: 1. Solid 2. Liquid 3. Gas 5

6. States of Matter Solid: definite shape and volume, molecules close together, rigid formation, little molecular movement (vibration). Particles in a solid are held together by very strong attractive forces (like strong magnets next to one another). There is an extremely small change in the volume of solids with changes in temperature and pressure. 6

7. Liquid: indefinite shape and definite volume, molecules further apart than solids, more molecular movement. Forces of attraction are a little weaker and allow particles to flow by one another (think of tipping a box of marbles – they will flow). Temperature and pressure changes have a small affect on the volume of liquids. 7

8. Gas: indefinite shape and volume. Molecules are far apart (no attractive forces between the particles because of the distance – think of magnets far away from one another. The most molecular movement (particles are in constant motion). Gas volumes are greatly affected by temperature and pressure changes. 8

9. Kinds of Change: physical change: no new substance is formed, properties such as size, shape, colour or state may change (example: Boiling water – have liquid water to start and water as a gas at the end or the heating element on a stove – black when off and red when on high and back t black when off again). Easily reversed. chemical change: new substances (with new properties) are formed from 2 or more reacting substances. (example: rusting of iron or burning paper) Not easily reversed. 9

10. Examples: 10

11. Classify the following as a physical or chemical change: A) freezing water B) burning gas C) melting butter D) stretching an elastic band E) rusting a nail F) tearing a piece of paper G) rotting an apple H) water freezing 11

12. Mixtures and Pure Substances : Matter can be broken down into two categories: 1. Pure substance : substances containing only one kind of matter (atoms or molecules). Examples: oxygen, water. 2. Mixtures : contains at least two kinds of matter that are physically mixed (blended) together (most things around us are mixtures). Mixtures are a combination of pure substances. Ex: salt water, air, salt and pepper, dirt.

13. Classification of matter 13

14. Glossary: Pure substance: contains one type of particle. –Elements: one kind of atom (Sulfur) –Compounds: contains at least two atoms of different elements bonded together (H 2 O) Mixture: contains two or more types of particles intermingling, no chemical bonding. –Homogeneous: uniform throughout only see one component (solution) –Heterogeneous: see the two components not uniform (salt and pepper mixed) 14

15. Composed of two or more different atoms Examples: water (H 2 O), 2 atoms of hydrogen, I atom of oxygen) salt (NaCl), 1 atom of sodium, 1 atom of chlorine 15

16. An element is a substance made up of only one kind of atom The periodic table arranges elements according to their properties 16

17. Heterogeneous 2 or more parts can be seen Different kinds of particles stay together. Mechanical (physical) mixing Ex: sand and salt, blood, milk 17

18. Homogeneous Appears to be one substance Particles are intermingled Are solutions (solute substance dissolved) (Solvent substance that is doing the dissolving) Ex: air, salt water (salt is the solute and water is the solvent) 18