Matter Match these: ObservationThe sky is blue. Fact Matter is made of atoms. TheoryThe cricket is chirping. LawPV=nRT HypothesisThe sick birds won’t sing as much because the disease damages their vocal cords.

Homework  Mystery Powder lab will be due Monday.

Objectives  Identify properties as being physical or chemical.  Practice making observations, predictions, and hypotheses. (All of this is gearing up for being able to put together your own experimental design.)

For Starters  If you would please… list as many things as you can think of that could be different depending upon what the thing or substance is.

Properties  A property is a quality that something possesses. We break down the properties of matter into two categories.  Physical Property: Can be observed without a chemical reaction of the substance.  Examples you can think of?

Properties  Chemical Property: Property having to do with the substance’s chemical reactions.  Can you think of examples for this one?

Changes  Likewise, physical changes are changes to a physical property, chemical changes changes to a chemical property. More precisely:  Physical Change: Changes the arrangement of the substance, but not what it is.  Chemical Change: Changes what the substance is at the molecular level.

Practice  A sticker to the pair who gets the most of these correct!  Identify whether each of these is a physical change or a chemical property.

Properties  Water boils at 100 degrees Celsius.  Diamonds are capable of cutting glass.  Water can be separated by electrolysis into hydrogen and oxygen.  Sugar is capable of dissolving in water.  Vinegar will react with baking soda.  Yeast acts on sugar to form carbon dioxide and ethanol.  Wood is flammable.  Ammonia is a gas at room temperature.  Bromine has a red color.

Properties  Water boils at 100 degrees Celsius. - PHYSICAL  Diamonds are capable of cutting glass. - PHYSICAL  Water can be separated by electrolysis into hydrogen and oxygen. - CHEMICAL  Sugar is capable of dissolving in water. - PHYSICAL  Vinegar will react with baking soda. - CHEMICAL  Yeast acts on sugar to form carbon dioxide and ethanol. - CHEMICAL  Wood is flammable. - CHEMICAL  Ammonia is a gas at room temperature. - PHYSICAL  Bromine has a red color. - PHYSICAL

Practice  Same deal, but now with changes.

Changes  A log is chopped into four equal pieces.  Water placed in a freezer turns to ice.  Iron rusts in a damp environment.  Sand and sugar are poured into a cup and shaken until evenly distributed.  Salt is dissolved in water.  Gasoline burns in the presence of oxygen.  Hydrogen peroxide decomposes to oxygen and water.

Changes  A log is chopped into four equal pieces. - PHYSICAL  Water placed in a freezer turns to ice. - PHYSICAL  Iron rusts in a damp environment. - CHEMICAL  Sand and sugar are poured into a cup and shaken until evenly distributed. - PHYSICAL  Salt is dissolved in water. - PHYSICAL  Gasoline burns in the presence of oxygen. - CHEMICAL  Hydrogen peroxide decomposes to oxygen and water. - CHEMICAL

Mystery Powder Lab  Practice making predictions and hypotheses.  Practice distinguishing between physical and chemical.  Today, complete page 1 only.  What might be examples of physical properties that powders could have? Chemical properties?

Properties and Changes  What is the difference between a physical and a chemical property?  What is the difference between a physical and a chemical change?

Mystery Powder Lab  Lab Safety  Goggles on!  Be careful handling liquids, some of them can stain your skin.  Thoroughly wash your glassware after each test.  You must check your procedure with me before you can continue.  Be sure that your observations ARE observations!