1. Chemical Change aka Chemical Reactions

2. Concept of Change Change an act of altering a substance an act of altering a substance

3. Physical Change  A change that occurs which does not change the identity of the substance

4. Signs of a Physical Change  Melting Ice  Freezing Kool-aid  Tearing paper  Boiling water

5. Chemical Changes  A change that occurs causing the identity of the substance to change

6.  New substance is formed  Has different properties  Mass does not change (Law of Conservation of Matter)

7. Indicators of a Chemical Change

8.  Light given off

9. Chemical Change  Presence of hot  Presence of cold

10. Chemical Change  Gas produced bubbling or fizzing bubbling or fizzing

11. Chemical Change  Solid precipitate

12. Chemical Change  Color change

13. Chemical Change  Odor given off Pewwwww!

14. Chemical Change  Smoke produced

15. Is it a chemical change? Decide if it is physical or chemical Then tell your reason

16. Smoke, color change and a temperature change  A forest fire destroys acres of land. There is a lot of smoke, and the trees turn to charcoal. Chemical

17. Water turns brown because the cocoa is brown  When making hot cocoa, clear water turns brown when you mix the cocoa in Physical

18. no new substance formed (melting )  Ice cream melts after it falls on the ground Physical

19. No new substance has formed (condensation)  On a hot day water forms on the outside of a cold glass of water Physical

20. Color change  A raw egg gets cooked Chemical

21. Gas formation  When Alka Seltzer is dropped into water it fizzes. Chemical

22. the paper is changing color because the crayon is red.  Red crayon changes white paper to red white paper to red Physical

23. The bubbles were already there, just under pressure in the bottle  Soda fizzes, and bubbles as you pour it in a glass Physical

24. Color change and temperature change  When you crack a glow stick, hydrogen peroxide mixes with other chemicals, causing it to glow and warm up. Chemical

25. Video time Bill Nye Bill Nye