1. Physical and Chemical Changes Unit 2—Part II Adapted by NCDPI – Unit 2 Matter is all around us

2. Concept of Change Change: the act of altering a substance https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact

3. Physical Change Physical change: a change that occurs that does not change the identity of the substance  Melting ice  Freezing Kool-aid  Tearing paper  Boiling water

4. Chemical Changes Chemical change: a change that occurs causing the identity of the substance to change  Burning paper  Digesting food  Electrolysis of water A chemical change is called a chemical reaction

5. Chemical Reaction Chemical reaction: occurs when the original substance changes form into a new substance. Some clues to a chemical reaction may include bubbles, smoke, a strong smell, color change, temperature change, or a sizzling sound

6. Indicator Indicator: something that produces an observable physical change but still retains its original form. Some of these changes may include the appearance or disappearance of a color. https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd

7. Chemical Changes Cont’d Indicators of a chemical change: Evolution of light Evolution of heat Evolution of a gas Color change Formation of a precipitate

8. Is it Physical or Chemical? ChangePhysicalChemical Melting cheese Burning wood Milk souring Wadding up paper Bicycle rusting