Chemistry 103OutlineDensity in ReviewChemical vs Physical???MatterPure Substances: CompoundsElements in a CompoundPure Substances Elements and CompoundsSlide 9MATTERMixturesSlide 12Slide 13Classification of MatterElements v. Compounds v. MixturesA closer look at Elements & The Periodic TableModern Periodic TableArrangement of the Periodic TableThe Periodic Table – All Stretched OutNames of Some Representative ElementsOrganization of the Periodic TableA closer look stillThe Conjecture of AtomsDalton’s Law of Atomic TheorySlide 25Atom DefinedSubatomic ParticlesElectron DiscoveredRutherford’s Gold-Foil ExperimentStructure of the AtomStructure of the AtomAtoms: Composed of 3 Subatomic ParticlesThe AtomSlide 34Atomic SymbolsAtomic NumberLearning CheckVariability in the Number of Electrons and NeutronsSlide 39Slide 40Slide 41Using Atomic Symbols to Calculate Numbers of Subatomic ParticlesSlide 43Chemistry 103Lecture 4Outline I. Matter Classified (CH3) II. The Periodic Table (CH4)- The “Atom” defined- History- Atomic Symbols- Atomic MassDensity in Review•What mass of gold (density = 19.3g/cm3) occupies the same volume as 80.0g of lithium (density = 0.534g/cm3)?Chemical vs Physical???•Popping a balloon•Burning a marshmellow•Snapping a twig•Water evaporating from a lake•Metabolizing a meal•Frying an eggMatter Pure Substance MixtureElement CompoundPure Substances: Compounds•Compounds –A chemical combination of 2 or more elements.–A pure substance that can be broken down into simpler substances by chemical means. Salt (NaCl)Table sugar (C12H22O11)Water (H2O)NOTE: CO is different from CoElements in a Compound“Table salt” is a compound that contains the elements sodium and chlorine.Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin CummingsPure SubstancesElements and Compounds•Elements and compounds have definite compositions, and each has a set of properties that are unique.•Which formulas represent elements (A) and which represent compounds (B)?–C (A)–CO2(B)–NH3(B)–C60(A)Matter Pure Substance MixtureElement CompoundMATTER•Mixtures: a physical combination of two or more pure substances in which each substance retains its own chemical identityMixturesA mixture is a type of matter that consists of:•Two or more substances that are physically mixed, not chemically combined•Two or more substances in different proportions•Substances that can be separated by physical methodsExample: Pasta and water can be separated with a strainer.Matter Pure Substance MixtureElement Compound Heterogeneous HomogeneousMixtures•Homogeneous Mixtures (solutions)–The composition is uniform throughout–The different parts of the mixture are not visible–air, salt water, alloys (i.e. brass, bronze)•Heterogeneous Mixtures–The composition of substances is not uniform–The composition varies from one part of the mixture to another –The different parts of the mixture are visible–potting soil, oil and waterClassification of MatterElements v. Compounds v. Mixtures•Identify each of the following as an element(A), compound(B), homogeneous mixture(C), or heterogeneous mixture(D).•carbon monoxide (CO) •oxygen (O2) •salt mixed with sugar •salt mixed with water •oil and waterA closer look at Elements &The Periodic TableModern Periodic Table•Mendeleev – Father of the Periodic Table•Periodic Law of the Elements – when elements are arranged in a particular order (increasing atomic number), elements of similar properties occur at periodic intervals•Arranged into:–Groups/families – vertical columns–Periods – horizontal rowshttp://www.woodrow.org/teachers/chemistry/institutes/1992/MENDELEEV.GIFArrangement of the Periodic TableThe blocks of the periodic table:The Periodic Table – All Stretched OutNames of Some Representative Elements•Several groups of representative elements are known by common names.Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin CummingsOrganization of the Periodic Table•Metals–Have luster, are malleable, conduct electricity•Nonmetals–Do not have the properties of metals•Metalloids–Have some metallic properties and some nonmetallic propertieshttp://www.travel-hotels-usa.com/media/United-States.gifA closer look stillThe Conjecture of Atoms•As early as 500 B.C., Greek Philosophers proposed that all matter is made up of atoms–Atom:•The smallest individual particle of an element that maintains the properties of that element•Atomos - indivisible http://www.aperfectworld.org/clipart/science_technology/atom.gifhttp://members.aol.com/dcaronejr/ezmed/atom.jpgDalton’s Law of Atomic Theory1. All matter is composed of extremely small particles called atoms.2. Atoms of a given element are identical in their physical and chemical properties.3. Atoms of different elements differ in their physical and chemical properties.http://www.kjemi.uio.no/software/dalton/graphics/john_dalton.gifDalton’s Law of Atomic Theory4. Atoms of different elements combine in simple, whole-number ratios to form compounds.5. In chemical reactions, atoms are combined, separated, or rearranged but never created, destroyed, or changed. http://www.kjemi.uio.no/software/dalton/graphics/john_dalton.gifAtom Defined•An atom is the smallest particle of an element that can exist and still have the properties of the element. The fundamental building block of matter.Subatomic ParticlesToday, we know that atoms are made up of smaller, more fundamental particles called subatomic particles.Protons, Electrons & NeutronsElectron Discovered•1898 - J.J. Thomson Proposed the “Raisin Muffin” model of the atom.e- e- e-Rutherford’s Gold-Foil Experiment Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin CummingsStructure of the Atom An atom consists•Of a nucleus that contains protons and neutrons•Of electrons in a large empty space around the nucleusCopyright © 2005 by Pearson Education, Inc.Publishing as Benjamin CummingsStructure of the Atom•An atom is composed of a nucleus and an area called the electron cloud–The nucleus is very small compared to the size of the atom –The nucleus contains the protons and the neutrons–The electrons are constantly moving around in the electron cloud–In a neutral atom, the number of electrons is equal to the number of protonsAtoms: Composed of 3 Subatomic ParticlesSymbol Relative Charge