Chemical and Pysical Changes

Ch. 12 - Lesson 5p. E68 E77Chemical ChangesPhysical change - When matter changes in size, shape, or state without changing what it is

Chemical change A change of matter that occurs when atoms link together in a new way creating a new substance different than the original substance

Examples of Chemical Changes

Label each one as an example of a physical or chemical change.BOILING WATER ________ TEARING CLOTHES ________ TARNISHING SILVER ________ LIGHTING A MATCH ________CHEWING A FOOD ________BREAKING A STICK ________RUSTING NAIL ________BURNING GAS IN A STOVE ________ MELTING ICE CREAM ________SAWING WOOD ________OXIDIZING FOOD FOR ENERGY ________ STRETCHING A RUBBER BAND ________Chemical reaction Another name for a chemical change.

Reactants Original substance before it goes through a chemical reaction

Products The new substances produced after a chemical change (reaction)

Signs of a chemical changeColor change Blueberry juice and baking soda will turn green

Formation of a gas Vinegar and baking soda will form carbon dioxide

Formation of light and heat Lighting a gas grillQuestions What is the difference between a chemical and physical change?

What happens during a chemical change?

What are three signs of a chemical change?

Why are chemical changes more difficult to reverse than physical changes?