Evidence of Chemical Change 10/20/11

I: Starter 10-21-11 In your “Starter” section: Make a list of the “signs” that a chemical reaction has occurred. Gas Formation Solid formation (precipitate) Temperature Change Color Change Light is given off Change in smell (or taste)

II: Practice Decide whether the following statements are physical changes or chemical changes. A bicycle left out in the rain begins to rust. Chemical A match burns, leaving only a charred stick of wood. A copper wire is cut into five smaller pieces. Physical An ice cube melts. Gasoline burns in a car engine.

Leaves of a maple tree turn bright red as winter approaches. A spoonful of sugar is dissolved in a cup of coffee Physical A silver knife and fork tarnish when they are exposed to air for several weeks. Chemical Leaves of a maple tree turn bright red as winter approaches. Water is heated and changed to steam. Food is digested in your stomach.

III: Application Make a visual display that divides your poster into 4 categories and includes : The definition for Chemical Change the middle of the paper Appropriate labels for each of the 4 categories Color Change Temperature Change Solid Precipitate Forms Gas Bubbles Graphic and written explanation demonstrating before and after for each of the 4 types of Chemical Changes

Evidence of Change Color Change Temperature Change Before After Before Illustration Illustration Illustration Illustration Don’t forget explanation of change being shown Evidence of Change by Insert First & Last Name Chemical Change – Any change that results in the formation of new chemical substances Explanation ….. Explanation ….. Solid Precipitate Gas Bubbles Before After Before After Illustration Illustration Illustration Illustration Explanation ….. Explanation …..

IV: Connections Make the following T-Chart Physical Change Chemical Change

V: Exit Write a paragraph summarizing today’s activity. Please make it at least 3-4 well written sentences!