Updated August 2006Created by C. Ippolito August 2006 Matter Objectives 1. explain why mass is used as a measure of the quantity of matter 2. describe the characteristics of elements, compounds, and mixtures 3. solve density problems 4. distinguish between physical and chemical properties 5. distinguish between physical and chemical changes 6. demonstrate an understanding of the law of conservation of mass

Updated August 2006Created by C. Ippolito August 2006 Matter anything that has mass and occupies space  Material  Material – a specific kind of matter wood steel copper sugar salt  Mass measures the quantity of matter nickel marble concrete milk

Updated August 2006Created by C. Ippolito August 2006 Material most matter made of two or more different materials  Heterogeneous Material non-uniform material separate particles can be discerned –when subdivided –examined more closely  Homogeneous Material uniform material uniform distribution of particles appears the same throughout –even when subdivided –even when examined more closely

Updated August 2006Created by C. Ippolito August 2006 Heterogeneous Materials separate parts are discernible  separates into discernible parts with passage of time PhasePhase –a physically separate part having a uniform set of properties InterfaceInterface –definite boundaries between phases in a heterogeneous material  Examples: Mixtures –contains more than one kind of material –sand and iron filings Granite –three mineral phases: quartz, biotite, feldspar Milk –two or more phases water, fat globules, proteins

Updated August 2006Created by C. Ippolito August 2006 Homogeneous Materials consist of only one phase  uniform distribution of particles  same properties throughout  does not separate into phases as time passes Examples:  copper  sulfur  salt solution (salt & water)  sugar solution (sugar & water)

Updated August 2006Created by C. Ippolito August 2006 Solutions homogeneous mixture  Solute material dissolved smaller portion of mixture  Solvent material that does dissolving larger portion of mixture  Molarity proportion of solvent to solute in specific solution –moles of solute/ 1000 g of solvent represented by symbol “M”

Updated August 2006Created by C. Ippolito August 2006 Substances homogeneous materials that always have the same composition  Elements composed of only one kind of atom 92 naturally occurring elements  Compounds composed of two or more different atoms –always exist in definite proportions by mass –properties are different from its constituents –decompose into simpler substances by chemical change

Updated August 2006Created by C. Ippolito August 2006 Properties of Substances Physical Properties Physical Properties  depend on the substance itself Chemical Properties Chemical Properties  depend on the action of the substance in the presence of other substances

Updated August 2006Created by C. Ippolito August 2006 Physical Properties Extensive Properties Extensive Properties  depend on the amount of material present Mass – measure in grams Length – measured in meters Volume – measured in milliliters (mL) or cubic centimeters (cm 3 ) Intensive Properties Intensive Properties  depend on the nature of the material always present regardless of the amount of material present

Updated August 2006Created by C. Ippolito August 2006 Density Density  measures quantity of mass of a substance that occupies one unit of volume  density = Malleability Malleability  can be hammered into thin sheets Ductility Ductility  can be drawn into fine threads or wires Conductivity Conductivity  amount of resistance to flow of heat or electricity conductorsconductors –little resistance to flow insulatorsinsulators – large resistance to flow Boiling Point Boiling Point  temperature of phase change from liquid to gas Melting Point Melting Point  temperature of phase change from solid to liquid Refractive Index Refractive Index  degree to which a substance bends light Intensive Properties

Updated August 2006Created by C. Ippolito August 2006 Physical Changes changes that only affect a substance’s physical properties  melt  melt – solid to liquid  boil  boil – liquid to gas  condense  condense – gas to liquid  freeze  freeze – liquid to solid  sublimate  sublimate – solid directly to gas separation of mixtures based on physical properties  Distillation – uses differences in boiling points  Fractional Crystallization – uses solubility at different temperatures

Updated August 2006Created by C. Ippolito August 2006 Chemical Changes occur when a substance changes so that one or more new substances with different properties are formed  burning  digesting  fermenting

Updated August 2006Created by C. Ippolito August 2006 Conservation of Mass Antoine LavoisierLavoisier  studied burning of metals to form calx  total mass of matter before and after chemical changes is the same in chemical changes matter is neither created nor destroyed, it only changes its form

Updated August 2006Created by C. Ippolito August 2006 Chemical Symbols alchemists used secret codes  signs for known elements shorthand used to represent elements  JJ Bersalius each element is represented a one or two letter symbol with the first letter always capitalized symbol derived from first letter of name, if already assigned take a second letter from name

Updated August 2006Created by C. Ippolito August 2006 Chemical Names and Symbols English named  aluminum (Al)  argon (Ar)  arsenic (As)  carbon (C)  calcium (Ca) Honorary named  Curium (Cm)  Californium (Cf) Latin named  iron [ferrum] (Fe)  silver [argentum] (Ag)  gold [aurum] (Au)  lead [plumbum] (Pb)  tin [stannum] (Sn) German named  tungsten [wolfram] (W)