Physical and Chemical Changes Physical Change Physical change

Physical and Chemical Changes

Physical Change • Physical change- substance changes without forming a new substance. Ex. Pour melted chocolate on ice cream. It still tastes the same because the particles have not changed, it just hardened (changed state) because the ice cream was cool. •

Chemical Change • Chemical Change- Always results in the formation of a new substance or substance Examples: Burning, Cooking, Rusting… The formation of water from hydrogen and oxygen.

Chemical Change Clues • • A new colour appears. Heat or light is given off. Bubbles of gas are given off. A solid material (called a precipitate) forms in a liquid. • The change is difficult to reverse.

Chemical or physical change? • Frying an egg? • Chemical change – New colour appears – Difficult to reverse

Chemical or Physical Change • Ice cubes melting • Physical Change – Change of State only – It is still WATER

Chemical or Physical Change • Baking cookies? • CHEMICAL Change New Substance Difficult to reverse

Chemical or Physical • Crumpling a piece of paper • Physical Change STILL PAPER Form has only changed

Physical or Chemical • Bread moulding • CHEMICAL CHANGE - New substance - Change in Colour - Can not reverse

Physical or Chemical • Apple turning brown • CHEMICAL CHANGE • New substance • Change in colour

Physical or Chemical • Formation or rain • PHYSICAL CHANGE Still Water

Physical or Chemical • Iron rusting • CHEMICAL CHANGE -Colour change

Physical or Chemical • Boiling water • PHYSICAL Change -still WATER

Physical or Chemical • Cutting diamonds PHYSICAL CHANGE They are still diamonds