SLIDE

2. Physical changes:Physical changes:
 Can easily be undone.Can easily be undone.
 Do not change into a different substance.Do not change into a different substance.
 Can change states(solid, liquid ,gas &Can change states(solid, liquid ,gas &
plasma).plasma).
 Temporary changeTemporary change
 Arrangement of molecules occursArrangement of molecules occurs

3. EXAMPLES OF PHYSICAL
CHANGE
 BREAKING AN OBJECT (2 PIECES OF A
PENCIL)
 CUTTING OF WOOD
 WATER BECOMING WATER VAPOUR
 MELTING OF WAX

5. Chemical changes:Chemical changes:
 Change in colour occurs.Change in colour occurs.
 Change in odor.Change in odor.
 Might produce a gas or precipitate.Might produce a gas or precipitate.
 Energy may be released or absorbed.Energy may be released or absorbed.
 Forms a new substance.Forms a new substance.
 Can not be easily reversed.Can not be easily reversed.
 Permanent changePermanent change

6. EXAMPLES OF CHEMICAL
CHANGE
• BURNING OF WOOD
• RUSTING OF IRON
• EXPLOSION OF CRACKERS

9. REMEMBER…
SOME THINGS THAT HINT A CHEMICAL
CHANGE HAS TAKEN PLACE
•HEAT OR LIGHT IS GIVEN OFF
•BUBBLES OF GAS ARE GIVEN OFF
•A PRECIPITATE IS FORMED
•THE CHANGE IS DIFFICULT TO REVERSE

12. CLASSIFY INTO CHEMICAL & PHYSICALCLASSIFY INTO CHEMICAL & PHYSICAL
CHANGESCHANGES
 SODIUM HYDROXIDESODIUM HYDROXIDE DISSOLVESDISSOLVES IN WATERIN WATER
 HClHCl REACTSREACTS WITH KCl TO PRODUCE A SALT,WITH KCl TO PRODUCE A SALT,
WATER,WATER,
AND HEATAND HEAT
 A PELLET OF SODIUM IS SLICED IN TWOA PELLET OF SODIUM IS SLICED IN TWO
 ICE MELTSICE MELTS
 MACARONI SALAD SPOILS IN THE SUNMACARONI SALAD SPOILS IN THE SUN
 WATER EVAPORATESWATER EVAPORATES
 COOKING BROWNIESCOOKING BROWNIES
 A BALLOON IS FILLED WITH AIRA BALLOON IS FILLED WITH AIR
 THE BODY DIGESTING FOODTHE BODY DIGESTING FOOD
 A CATERPILLAR TRANSFORMING INTO AA CATERPILLAR TRANSFORMING INTO A