Copyright © by Houghton Mifflin Company. All rights reserved. Chapter 2 Atoms, Molecules, and Ions.

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<ul><li> Slide 1 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Chapter 2 Atoms, Molecules, and Ions </li> <li> Slide 2 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. What is atom? Electron Nucleus Atomic Structure </li> <li> Slide 3 </li> <li> Copyright Cengage Learning. All rights reserved 3 Greeks were the first to attempt to explain why chemical changes occur. Alchemy dominated for 2000 years. Several elements discovered. Mineral acids prepared. Robert Boyle was the first chemist. Performed quantitative experiments. Developed first experimental definition of an element. Early History of Chemistry </li> <li> Slide 4 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. The Discovery of Electrons J.J. Thomson CRT experiment Robert Millikan Oil droplets experiment </li> <li> Slide 5 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Early Experiments to Characterize the atom Measurement of electron J.J. Thomson (1856-1940) Cathode-ray tube experiment (1898-1903) e/m = -1.76 10 8 C/g </li> <li> Slide 6 </li> <li> J. J. Thomson (18981903) Postulated the existence of negatively charged particles, that we now call electrons, using cathode-ray tubes. Determined the charge-to-mass ratio of an electron. The atom must also contain positive particles that balance exactly the negative charge carried by electrons. Copyright Cengage Learning. All rights reserved 6 </li> <li> Slide 7 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Cathode-ray tube </li> <li> Slide 8 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Deflection of rays </li> <li> Slide 9 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Plum-pudding model </li> <li> Slide 10 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Early Experiments to Characterize the atom Measurement of electron weight Robert Millikan (1868-1953) Nobel Prize in Physics in 1923 Oil droplets experiment (1909) m = 9.11 X 10 -31 Kg </li> <li> Slide 11 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. </li> <li> Slide 12 </li> <li> Early Experiments to Characterize the atom Ernest Rutherford (1871-1937) Nobel Prize in Chemistry in 1908 </li> <li> Slide 13 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. The Results from Rutherford The majority of a particles penetrated the foil undeflected.( ) Some particles experienced slight deflections. ( ) A few (about one in every 20000) suffered rather serious deflections as they penetrated the foil. ( ) A similar number did not pass through the foil at all but bounced back in the direction from which they had come.( ) </li> <li> Slide 14 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Thomsons model Rutherfords model </li> <li> Slide 15 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. The Model of Rutherford Most of the mass and all of the positive charge of an atom are centered in a very small region called the nucleus. ( ) The atom is mostly empty space. The magnitude of the positive charge is different for different atoms and is approximately one half the atomic weight of the element.( 1/2) There exist as many electrons outside the nucleus as there are units of positive charge on the nucleus. The atom as a whole is electrically neutral.( ) </li> <li> Slide 16 </li> <li> Henri Becquerel (1896) Discovered radioactivity by observing the spontaneous emission of radiation by uranium. Nobel Prize in Physics in 1903 Three types of radioactive emission exist: Gamma rays ( ) high energy light Beta particles () a high speed electron Alpha particles () a particle with a 2+ charge Copyright Cengage Learning. All rights reserved 16 </li> <li> Slide 17 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Founder of Radioactivity Marie Sklodowska Curie ( Poland 1867-1934) Found new element polonium (Po ) in 1898 Nobel Prize in Physics in 1903 Found new element radium (Ra ) in 1898 Nobel Prize in chemistry in 1911 </li> <li> Slide 18 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. </li> <li> Slide 19 </li> <li> Modern View of Atomic Structure </li> <li> Slide 20 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Isotopes of Elements </li> <li> Slide 21 </li> <li> Isotopes are identified by: Atomic Number (Z) number of protons Mass Number (A) number of protons plus number of neutrons Copyright Cengage Learning. All rights reserved 21 </li> <li> Slide 22 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Components of Atoms in Physics (quark) +2/3 u (up quark) m 0.01GeV c (charm quark) m 1.5GeV t (top quark) m 89GeV -1/3 d (down quark) m 0.01GeV s (strange quark) m 0.15GeV b (bottom quark) m 5.5GeV (lepton) 0 v (electron neutrino) m 2 10-8GeV v(muon neutrino) m 2 10 4 GeV v (tau neutrino) m 0.035GeV e (electron) m 5.11 10 -4 GeV (muon) m 0.106GeV (tau) m 1.75GeV </li> <li> Slide 23 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Naming Simple Compounds Binary Compounds (Type I; Ionic) Binary Compounds (Type II; Ionic) Binary Compounds (Type III; Contain Two Nonmetals) </li> <li> Slide 24 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Binary Compounds (Type I; Ionic ) Rules 1. The cation is always named first and anion second. 2. A monatomic cation takes its name from the name of element. 3. A monatomic anion is named by taking the first part of the element name and adding ide. </li> <li> Slide 25 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. </li> <li> Slide 26 </li> <li> Naming Compounds For Type I 1. NaCl 2. NaH 3. KI 4. MgO 5. BN </li> <li> Slide 27 </li> <li> Binary Ionic Compounds (Type II) Metals in these compounds form more than one type of positive ion. Charge on the metal ion must be specified. Roman numeral indicates the charge of the metal cation. Transition metal cations usually require a Roman numeral. Elements that form only one cation do not need to be identified by a roman numeral. Copyright Cengage Learning. All rights reserved 27 </li> <li> Slide 28 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. IonSystematic Name Fe +3 Iron(III) Fe +2 Iron(II) Cu +2 Copper(II) Cu + Copper(I) Co +3 Cobalt(III) Co +2 Cobalt(II) Sn +4 Tin(IV) Sn +2 Tin(II) Pb +4 Lead(IV) Pb +2 Lead(II) </li> <li> Slide 29 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Binary Compounds (Type II; Ionic) Rules for Polyatomic Ions 1. Contain polyatomic ions. ex. NH + 4, CN -, SO 4 -2 2. Polyatomic ions are assigned special names that must be memorized to name the compounds. 3. For oxyanions, the name of the one with the smaller number of oxygen atoms ends in ite, and the name of the one with the larger number of oxygen atoms ends in ate 4. When more than two oxyanions make up a series, hypo- (less than) for fewest oxygen atoms and per- (more than) for the most oxygen atoms are used. </li> <li> Slide 30 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. </li> <li> Slide 31 </li> <li> Binary Compounds (Type II; Ionic) CoBr 2 CaCl 2 Al 2 O 3 CrCl 3 </li> <li> Slide 32 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Binary Compounds (Type III; Contain Two Nonmetals) Rules 1. The first element in the formula is named first, using the full element name. 2. The second element is named as if it was an anion. 3. Prefixes are used to denote the numbers of atoms. 4. The prefix mono- is never used for naming the first element. </li> <li> Slide 33 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. PrefixNumber Indicated Mono-1 Di-2 Tri-3 Tetra-4 Penta5 Hexa-6 Hepta-7 Octa-8 Nona-9 Deca-10 </li> <li> Slide 34 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Problems for naming CuI NaClO 4 SF 2 Mg(OH) 2 Ag 2 CrO 4 Li 3 N </li> <li> Slide 35 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Question Which is not the correct chemical formula for the compound named? potassium phosphate, K 3 PO 4 iron(II) oxide, FeO calcium carbonate, CaCO 3 sodium sulfide, NaS lithium nitrate, LiNO 3 </li> <li> Slide 36 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Answer d)sodium sulfide, NaS Sodium sulfide is a binary compound composed of a Group 1 element, whose charge in compounds is +1, and a Group 16 element, whose charge in binary compounds is commonly 2. This means that two sodium ions must be combined with one sulfide ion to form a neutral compound. </li> <li> Slide 37 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Question Which of the following is not the correct chemical formula for the compound named? Li 2 O, lithium oxide FePO 4, iron(III) phosphate HF, hydrogen fluoride BaCl 2, barium dichloride Mg 3 N 2, magnesium nitride </li> <li> Slide 38 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Answer d)BaCl 2, barium dichloride The binary compound, BaCl 2, is composed of a metal and a nonmetal. Its correct name is barium chloride (no prefix is needed). </li> <li> Slide 39 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Question Which is the correct formula for copper(I) sulfide? CuS Cu 2 S CuS 2 Cu 2 S 2 None of the above </li> <li> Slide 40 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Answer b)Cu 2 S The copper(I) ion has a +1 charge and the sulfide ion has a 2 charge. </li> <li> Slide 41 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Question What is the correct name for this compound with the formula Mg 3 (PO 4 ) 2 ? Trimagnesium diphosphate Magnesium(II) phosphate Magnesium phosphate Magnesium(II) diphosphate Magnesium(III) diphosphate </li> <li> Slide 42 </li> <li> Copyright by Houghton Mifflin Company. All rights reserved. Answer c)Magnesium phosphate The magnesium ion has a +2 charge and the phosphate ion has a 3 charge. </li> </ul>

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