Presentation on theme: "Classifying Matter Matter Elements Compounds Mixtures"— Presentation transcript:
1Classifying Matter Matter Elements Compounds Mixtures Scientists classify matter according to make-up.MatterElementsCompoundsMixtures
2Elements Simplest pure substance – fixed composition. Pure substance is made of only one material. Same throughout. Referred to as homogeneous matter.Are made of alike atoms, which are the basic building blocks of matter.Represented by chemical symbols - H, O, Al, Cu, Au.118 elements organized in the periodic table in squares called an element key.
3Element Key Atomic Number I.D’s the element Symbol Element Name Atomic MassI.D’s the elementrepresents elementsmass of element (amu’s)
4Elements/Symbols Calcium Tin Uranium Magnesium Phosphorus Iron iodine SilverHeliumMercuryNickelSiliconSulfurCopperChromiumAluminumBromineHydrogenZincPotassiumOxygenLeadLithiumGoldFluorineNeonNitrogenSodiumCarbonChlorine
5Compounds Two or more elements chemically combined. Represented by chemical formulas.Examples: H2O, CO2, NaCl, C12H22O11Molecules are the smallest natural unit of a compound or diatomic element. A molecule is made up of two or more atoms chemically combined.
6Chemical FormulasCombination of chemical symbols that represents compounds.Sometimes represents a molecule of an element. Example: O2, N2, Cl2 called diatomic elements – two atoms of the same element.Subscripts are the # of atoms of an element - H2OCoefficients are the # placed in front of chemical formula. Represents # of molecules of a compound H2O
7Identifying Substances Elementor CompoundSymbol or FormulaAtomor MoleculeFluorine (F)Water (H2O)Chlorine gas (Cl2)ElementSymbolAtomCompoundFormulaMoleculeElementFormulaMolecule
8Found in milk of magnesia Counting AtomsNameUseFormulaAtoms in FormulaCalcium carbonateChalkCaCO3Magnesium hydroxideFound in milk of magnesiaMg(OH)2Phosphoric acidDetergents3H3PO4Trinitrotoluene (TNT)Explosive2C7H5(NO2)3Ca=1C=1O=3Mg=1O=2H=2H=9P=3O=12C=14 N=6H=10 O=12
9Calculating Formula Mass Formula mass of a compound is the sum of the atomic weights of all atoms in a chemical formula.Examples: Atoms Atomic Mass TotalsH2O 2 of H x1 of O x18.0 amuC12H22O of C x22 of H x11 of O x342.0 amu
10MixturesTwo or more substances mixed together but not chemically combined.Has unlike parts and a composition that varies from sample to sample.Properties:Sub. in a mixture keep their separate identities.Sub. can be present in any amount.Sub. can be separated out by physical means.
12Heterogeneous Mixtures The least-mixed.Doesn’t appear to be the same throughout.Particles large enough to be seen.Examples: sand, dirt, concrete, suspensions, etc.
13Homogeneous Mixtures Well-mixed. Same throughout a given sample. Examples: air, soda, toothpaste, lotions, etc.
14Solutions A homogeneous mixture. One substance dissolves in another. Solutions remain constantly & uniformly mixed.Examples: lemonade, soda, ocean water, antifreeze, metal alloys (steel, brass), etc.
15Colloids A homogeneous mixture. Mixed together but not dissolved. Appears cloudy. Scatters light.Examples: milk, cool whip, toothpaste, lotions, fog, paint, etc.