2. MATTER: MIXTURES AND ELEMENTS AND COMPOUNDS

3.  You will distinguish between physical and chemical properties  You will classify matter by composition.  You will explain the fundamental law of the conservation of mass WHAT YOU’LL LEARN

4.  A mixture is a combination of two or more substances in which each pure substance retains its individual chemical properties  This is a physical blending, not a chemical blending.  Composition of the mixture can vary  Can be physically separated MIXTURES

5.  Heterogeneous Mixture- one that does not blend smoothly throughout and which the individual substances remain distinct  Examples: Sand and Water, Oil and Water, Cement  Homogeneous Mixture (Solutions)- has constant composition throughout; it always has a single phase  Examples: salt water, vinegar, alloys HETEROGENEOUS VS. HOMOGENOUS

6.  Magnet  Filter  Decant  Evaporation  Centrifuge  Chromatography  Distillation METHODS OF SEPARATING MIXTURES

7.  A technique that uses a porous barrier to separate a solid from a liquid FILTRATION

8.  A technique that is based on differences in the boiling points of substances DISTILLATION

9.  A technique that results in the formation of pure solid particles of a substance from a solution containing the dissolved substance CRYSTALLIZATION

10.  A technique that separates the components of a mixture on the basis of the tendency of each to travel or be drawn across the surface of another material CHROMATOGRAPHY

11.  Elements- are the simplest form of matter that can exist under NORMAL laboratory conditions  Cannot be separated into simpler substances by chemical means  Are the building blocks for all other --substances  Compounds- are substances that can be separated into simpler substances by chemical means ELEMENTS AND COMPOUNDS

12.  Elements comprising compounds combine in definite proportions  Regardless of the amount, a compound is always composed of the same elements in the same proportion by mass LAW OF DEFINITE PROPORTIONS WaterMethane

13.  Percent by Mass- the ratio of the mass of each element to the total mass of the compound as a percentage PERCENT BY MASS

14.  A 78.0g sample of an unknown compound contains 12.4 g of hydrogen. What is the percent by mass of hydrogen in the compound? PRACTICE PROBLEM 15.9% Hydrogen

15. MORE PRACTICE MaterialPure Substance or Mixture Element, Compound, Homogeneous, Heterogeneous Limestone (CaCO 3 ) Air Bronze Copper Sugar + water Concrete Pure Water Caffeine

16. MaterialPure Substance or Mixture Element, Compound, Homogeneous, Heterogeneous Limestone (CaCO 3 )PURE SUBSTANCECOMPOUND AirMIXTUREHOMOGENEOUS BronzeMIXTUREHOMOGENEOUS CopperPURE SUBSTANCEELEMENT Sugar + waterMIXTUREHOMOGENEOUS ConcreteMIXTUREHETEROGENEOUS Pure WaterPURE SUBSTANCECOMPOUND CaffeinePURE SUBSTANCECOMPOUND MORE PRACTICE!

17. SUMMARY MATTE R Matter Substance Definite composition (homogeneous) Substance Definite composition (homogeneous) Element (Examples: iron, sulfur, carbon, hydrogen, oxygen, silver) Element (Examples: iron, sulfur, carbon, hydrogen, oxygen, silver) Mixture of Substances Variable composition Mixture of Substances Variable composition Compound (Examples: water. iron sulfide, methane, aluminum, silicate) Compound (Examples: water. iron sulfide, methane, aluminum, silicate) Homogeneous mixture Uniform throughout, also called a solution (Examples: air, tap water, gold alloy) Homogeneous mixture Uniform throughout, also called a solution (Examples: air, tap water, gold alloy) Heterogeneous mixture Nonuniform distinct phases (Examples: soup, concrete, granite) Heterogeneous mixture Nonuniform distinct phases (Examples: soup, concrete, granite) Chemically separable Physically separable

18.  Read Oobleck Lab-There will be a QUIZ before the lab over what you will be doing!  Make sure you bring the lab back-you will not receive another one. =)  Book work:  PAGE 69: 15-17  PAGE 76: 21-23  PAGE 77: 25-27, 30 HOMEWORK =)

19.  Work on Classifying Matter Worksheet  If you finish-read Oobleck Lab FOR THE REMAINDER OF CLASS