1. Changes and Particle Theory

2. What is the colour of these solids ? colourless

3. Physical Properties Colour is one of the physical properties of a substance. Can you tell me some other physical properties of a substance ? State Melting point Boiling point Taste

4. Table saltWaterChlorine colourcolourless Pale green StateSolidLiquidGas Melting point 808  C 0C0C-101  C

5. Physical change is a change in which no new substances are formed. Water water vapour

6. Examples of physical change Dissolving salt in water Water turns into ice Ice-cream changes into liquid Evaporation Boiling Condensation Freezing Melting Sublimation

7. A change is a change in which one or more new substances are formed. Burning always is a chemical change. Wood carbon dioxide

8. Decide whether each of the following is physical or chemical change: Breaking a glass cup Burning coal in air Frying an egg Evaporating salt solution to dryness

9. Particle theory of Matter Iodine( 碘 ) particles leave the solid and mix with the alcohol particles.

10. Three States of Matter Solids, Liquids, Gases

11. Which of following is a chemical property ? A.Tastes like alcohol. B.Burns in air. C.Mixes in all proportions with water. D.Colourless.