<p> UNIT 3: ATOMIC THEORY</p><p>I. Atomic Theory • Chemical Reaction: the transforming a substance into one or more______. • Up until the end of the 18th century chemists believed that an element couldn’t be further broken down by ordinary chemical means. A. Laws: 1) Law of Conservation of Mass: ______</p><p>2) Law of Definite Proportions: ______– Salt- always 39.34 % Na and 60.66 % Cl</p><p>B. Dalton’s Atomic Theory 1) All mater is composed of ______2) Atoms of a given element are ______in ______, ______, and other properties; atoms of ______elements ______in ______, ______, and other properties 3) Atoms ______be subdivided, ______, or______. 4) Atoms of ______elements combine in simple whole- number ratios to form ______compounds. 5) In chemical reactions, atoms are______, ______, or ______. </p><p>C. Modern Atomic Theory 1) Atomic Structure: a) Atom: the ______particle of an element that ______the chemical properties of the element. b) All atoms consist of ______regions: 1) Nucleus: ______. 2) Electron Cloud: surrounding the nucleus is a ______. 2) Subatomic Particles • Proton:______. – Mass: 1.673 x 10 -27 kg – Symbol: </p><p>• Electron: ______. – Mass: 9.108 x 10 -31 kg (found by Robert Millikan) – Symbol: </p><p>• Neutron: ______. – Mass: 1.675 x 10 -27 kg – Symbol: </p><p>3) Discoveries A) Discovery of the Electron 1) J.J. Thomson’s Cathode ray tube: glass tube where electric current is passed through. Paddle moved, cast shadow, deflected from - 2) Conclusion: ______.</p><p>B) Discovery of the Nucleus 1) Ernest Rutherford’s Gold Foil Experiment 2) Bombarded a thin, gold foil with positively charged particles, with high mass 3) Result: ______, so there must be a ______- he called it the ______</p><p>– Atoms, Ions, and Isotopes: 1) The Periodic Table: a. Atomic Number: ______– On Periodic Table-elements are placed in order of ______. – Atomic number ______an element – Because atoms are ______- atomic number also indicates ______. b. Mass Number : ______plus ______for a particular atom c. Atomic Mass: ______. d. Molar Mass: the ______of ______of a pure substance (units______) – numerically ______to the ______of the element (found in Periodic Table of Elements) – one mole of Helium has a mass of ~ ______– can be used as a ______. e. Mole (mol) : the ______that contains as many particles as there are ______in exactly ______of carbon-12 – it is a counting unit (______) f. Avogadro’s Number: the ______in exactly ______of a ______substance. – 6.02211367 x 10 23 or 6.022 x 10 23 2) Atoms a. All atomic nuclei are made up of ______and ______. b. The proton and neutron are almost ______in ______and ______. c. atoms are electrically neutral because they contain ______number of ______and ______. d. Atoms of ______elements have ______. e. Atoms of ______element have ______. f. The number of ______identify the atom</p><p>3) Isotopes: a. NEUTRONS CHANGE b. ______of an element that are ______alike but______. c. isotopes have the ______number of______, but ______number of______. d. Isotopes have ______. – usually one type of Isotope is predominant </p><p>EXAMPLE: 75% 133Cs, 20% 132Cs, 5% 134Cs. What is average atomic mass? ______x______= ______x______= ______x______= ______TOTAL = ______4) Ions: a. ELECTRONS CHANGE b. Used to be atoms, but______were either ______or ______. c. Electrons are______! d. Lose electrons: atom becomes ______negative or ______positive, so there is a ______charge e. Losing 2 electrons, gives a ______charge f. Gain electrons: atom becomes ______negative, so there is a ______charge g. Losing 3 electrons, gives a ______charge</p><p>5) Examples: Identify the number of protons, neutrons, and electrons from the following: II. Introduction to the Periodic Table A. Groups or families: – the ______-______of the periodic table – numbered from ______from ______to ______. – each group contains elements with ______chemical properties</p><p>B. Periods: – the ______of elements in the periodic table – physical and chemical properties ______somewhat regularly ______a period. Elements that are ______in the ______period are often ______than those ______. </p><p>C. Three Major Categories of Periodic Table: 1) Metals: ______. 2) Non-Metals: ______. 3) Metalloids: along the stair–step line. </p><p>1) Metals: – an element that is a ______of ______and______. (like Copper) – Malleability:can be ______into thin sheets. – Ductile:can be ______into a ______. – Metallic luster- usually ______or ______(not Au/Cu)</p><p>A. Alkali metals: group _____ elements – highly ______-because they want to ______. – don’t exist in nature, by themselves – react ______with ______- K bursts into flames – Electrolytes: K and Na ions needed to ______functions. They ______from the ______to the muscle. </p><p>B. Transition metals: group ______C. Alkaline Earth Metals: group ______elements – not as ______as group 1, but still very ______– ______than group 1 and therefore ______.</p><p>2. Non-Metals: – an element that is a ______of ______and______. (like Phosphorous) – Many non-metals are ______at room temperature – Gas: ______, ______, ______, ______– Liquid: ______– Solid:______, ______, ______, ______, ______– tend to be______, not______. </p><p>A. Halogens: Group ______– ______nonmetals (They want to ______), so ______exit freely in nature. – Antibacterial agents</p><p>B. Noble Gases: ______elements found in group ______– All are ______at room temperature – have a ______(______electrons in outer energy level) – Neon, Argon, Krypton, Xenon, are all found in lighting. </p><p>3. Metalloids: – element that has ______characteristics of ______and ______characteristics of ______. – ______that separates ______from ______on the periodic table – All are ______at room temperature – Tend to be ______than metals but ______as ______as non-metals – ______of electricity: ability is somewhere ______. – used in______, ______, digital watches, ______, and radios III. Elements • 108 different elements are known, ______occur naturally • ______is most abundant 49%, ______is 26%</p><p>H-______Li- ______Na- ______K- ______Rb- ______Cs- ______Fr- ______Be- ______Mg- ______Ca-______Sr- ______Ba- ______Ra- ______B- ______Al- ______C- ______Si- ______N- ______P- ______O- ______S- ______F- ______Cl- ______He- ______Ne- ______Ar- ______Cr- ______Cu- ______Au- ______Ag- ______Zn- ______Fe- ______Ni- ______Sn- ______Pb- ______Br- ______I- ______</p><p>IV. Compounds and Mass</p><p>A. Compound: – ______.</p><p>B. Mass of Compounds: H2O 1) determine the ______of ______element in the compound 1 mole of Hydrogen = ______g or ____g 1 mole of Oxygen = ______g or ____g</p><p>2) ______each ______by ______moles of H x ______g/mol = ____ g ____ mole of O x ______g/mol = ____ g</p><p>3) Then add: ___g + ____g = _____ g in H2O</p><p>Find the mass of NO2 Mass of N = </p><p>Mass of O = Mass of N + Mass of O = </p><p>Find the mass of C6H12O6</p><p>C. Conversions Using Atomic Mass • The ______always goes with ______and it is always ______</p><p>• 3.5 mole Carbon, is how many grams?</p><p>3.5 mol C x = grams C</p><p>• 54 grams H2O, is how many moles?</p><p>54 g H2O x = mol H2O</p><p>PROBLEMS: *Always figure out the mass of the element or compound first, then convert using the atomic mass</p><p>1) How many grams are in 3.89 mol of Calcium? Atoms?</p><p>2) How many grams are in 2.05 mol of N2O5? Molecules? 3) How many molecules are in 327 g of H2SO4? </p>