Preview General Organic Chemistry Structures Of Life, 6th Edition by Karen Timberlake

Preview General Organic Chemistry Structures Of Life, 6th Edition by Karen Timberlake Preview General Organic Chemistry Structures Of Life, 6th Edition by Karen Timberlake Preview General Organic Chemistry Structures Of Life, 6th Edition by Karen Timberlake Preview General Organic Chemistry Structures Of Life, 6th Edition by Karen Timberlake Preview General Organic Chemistry Structures Of Life, 6th Edition by Karen Timberlake

General, Organic, and Biological Chemistry STRUCTURES OF LIFE This page intentionally left blank General, Organic, and Biological Chemistry STRUCTURES OF LIFE Sixth Edition Karen Timberlake Contributions by MaryKay Orgill, Ph.D University of Nevada, Las Vegas @ Pearson 330 I Judson Street, !XV NY 10013 Courseware Portfolio Man a ger: Scott Dustan Direct or, Courseware Portfolio Management: Jeanne Zalesky Content Produ cer: Melanie Field Managin g Producer: Kristen R athman Courseware Analyst: Coleen Morrison Coursewar e Dirfftor, Content Deve-l opment: Jennifer Hart Coursewar e Editor ial Assi.•tant: Fr•n Falk and Leslie Lee Rich Media Content Produt-er: P.•ula lborr• Fuli.Service Vendor: SPi Global Full Service Pr oject Manager: Christian Arsenault Copyeditor: Karen Slaght Design Manager: Maria Guglielmo Walsh Cover and Interior Designer: Tamara Newnam Courseware Portfo lio Analyst , Cont ent Dewlopment, Art: Jay McElroy Photo and IIJustration Project Manager: Stephanie Marquez lmagineering Art Rights and Permissions Pr oject Manager: Mall Perry Rights and Permissions Management: Ben Ferrini Photo Researcher: Clare Maxwell Manufacturing Buyer: Stacey Weinberger Produ 2019 20 15,2013, 2010 2007 by Pearson Education Inc All Rights Resen•ed Printed in the United States o f America This publication is protected by copyright and permission should be obtained from the publisher prior to any prohibited reproduction stor.tge in a retrieval system, or tr.msmission in any form or by any means e lectronic mechanical, photocopying, recording, or otherwise For infom1ation regarding permissions, request fom1s and the appropriate contact~ within the Pearson Education Global Rights & Permissions department, please visit www.pearsoned.com/pem1issions/ Acknowledgement'i of third party content appear on page C · l , which constitutes an extension o f this copyright page PEARSON, ALWAYS LEARNING, and Mastering" ' Chemistry are exclusive trademarks in the U.S and/or other countries owned by Pearson Education, Inc or its affiliates Unless otherwise indicated herein any third· party trademarks that may appear in this work are the property of their respective owners and any references to th ird-party trademarks logos or other trade dress are for demonstrative or descriptive purposes only Such references are not intended to imply any sponsorship, e ndorsement., authorization, or promotion of Pearson's product'i by the owners of such marks, or any relationship between the owner and Pearson Education Inc or iL~ affiliates, authors, Hcensees or distributors Library of Congr ess Cataloging-in-Publication Data Names: Timberlake, Karen C a uthor I Orgill, Mary Kay 1974Title: General, organic and biological chemistry : structures of life I Karen Timberlake; contributions by Mary Kay Orgill Ph.D., profe.ssor o f chemistry University o f Nevada Las Vega'i Description: Sixth edition I San Fr.mcisco CA : Pearson Education Inc., c2019 Identifiers: LCCN201704 170211SBN 9780 134730684 (hardcover) I ISBN 0134730682 Subjecls: LCSH: Chemistry Textbooks Classification: LCC QD33.2 T56 20 I I DOC 540 dc23 LC record available at hups:l/locn.Joc.gov/20 I 704 I 702 18 ISBN- 10: 0- 134-73068-2 JSBN- 13: 978-0- 134-73068-4 @Pearson www.pearsonh ighered.com Chemistry and Measurements 26 Matter and Energy 63 Atoms and Elements 99 Nuclear Chemistry 145 Chemistry in Our Lives Ionic and Molecular Compounds 174 Chemical Reactions and Quantities 223 Gases 275 10 Solutions 310 11 12 Acids and Bases 382 13 14 15 16 Alcohols, Phenols, Thiols, and Ethers 467 Reaction Rates and Chemical Equilibrium 355 Introduction to Organic Chemistry: Hydrocarbons 426 Aldehydes and Ketones 496 Carbohydrates 521 Carboxylic Acids and Esters 560 17 Lipids 586 18 Amines and Amides 624 19 Amino Acids and Proteins 660 20 Enzymes and Vitamins 688 21 22 23 Nucleic Acids and Protein Synthesis 721 Metabolism and Energy Production 802 24 Metabolic Pathways for Lipids and Amino Acids 825 Metabolic Pathways for Carbohydrates 764 v CHEMISTRY LINK TO HEALTH Concept Map 55 Chapter Review 55 KeyTerms 56 Key Math Skill 56 Core Chemistry Skills 57 Understanding the Concepts 57 Additional Practice Problems 59 Challenge Problems 60 Answers 60 Chemistry in Our Lives CAREER Forensic Scientist CLINICAL UPDATE the Crime Forensic Evidence Helps Solve 1.1 Chemistry and Chemicals 2 Scientific Method: Thinking Like a Scientist CHEMISTRY LINK TO HEALTH Paracelsus CLINICAL UPDATE the Crime 20 Early Chemist: 1.3 Studying and l earning Chemistry 1.4 Key Math Skills for Chemistry 1.5 Writing Numbers in Scientific Notation 17 Forensic Evidence Helps Solve CAREER 3.1 Dietitian 63 CLINICAL UPDATE A Diet and Exercise Program 63 Classification of Matter 64 CHEMISTRY LINK TO HEALTH Mixtures 66 CHEMISTRY LINK TO HEALTH Temperature 74 3.4 Energy 3.6 Specific Heat 80 3.7 Changes of State CAREER Registered Nurse 26 CLINICAL UPDATE Greg 's Visit with His Doctor 26 Units of Measurement 27 Measured Numbers and Significant Figures Signif icant Figures in Calcu lations Prefixes and Equalities 32 36 Writing Conversion Factors 40 Problem Solving Using Unit Conversion 44 CHEMISTRY LINK TO HEALTH Toxicology and Risk- Benefit Assessment 47 2.7 Density 49 30 Variation in Body 77 CHEMISTRY LINK TO HEALTH Weight 79 26 67 74 3.5 Energy and Nutrition Chemistry and Measurements Breathing States and Properties o f Matter 3.3 Temperature 70 vi Matter and Energy 63 Concept Map 20 Chapter Review 21 Key Terms 21 Key Math Skills 21 Understanding the Concepts 23 Additional Practice Problems 23 Challenge Problems 24 Answers 24 2 2 Bone Density 51 CLINICAL UPDATE Greg's Visit w ith His Doctor 54 Losing and Gaining 82 CHEMISTRY LINK TO HEALTH St eam Burns 87 CLINICAL UPDATE A Diet and Exercise Program 88 Concept Map 89 Chapter Review 89 KeyTerms 90 Core Chemistry Skills 91 Understanding the Concepts 92 Additional Practice Problems 93 Challenge Problems 95 Answers 95 Combining Ideas from Chapters to 97 Answers 98 Contents vii 5.5 Atoms and Elements 99 CAREER 4 Farmer CHEMISTRY LINK TO HEALTH 5.6 99 102 Elements Essential CHEMISTRY LINK TO HEALTH to Health 105 The Atom 107 4 Atomic Number and Mass Number 110 CHEMISTRY LINK TO THE ENVIRONMENT Many Forms of Carbon 111 4.5 4.6 Isotopes and Atomic M ass 113 Electron Energy l evels 117 Biological Reactions CHEMISTRY LINK TO HEALTH to UV Light 117 Electron Configurations 122 Trend s in Periodic Properties 129 Concept Map 136 Chapter Review 136 Key Terms 137 Core Chemistry Skills 138 Understanding the Concepts 139 Additional Practice Problems 141 Challenge Problems 142 Answers 142 CAREER 5.2 145 N uclear Reactions 5.4 145 Cardiac Imaging Using a N atural Radioactivity 146 149 Radiation Measurement Pharmacy Technician Radon in Our 156 CHEMISTRY LINK TO HEALTH Food 157 Radiation and Half-life of a Radi oisotope 159 174 Compounds at the Ions: Transf er of Electrons 175 CHEMISTRY LINK TO HEALTH Some Important Ions in the Body 179 Ionic Compounds Naming and Writing Ionic Fo rmulas Polyatomic Ions Molecular Compounds: Sharing Electrons 6.6 lewis Structures for Molecules and Polyatomic Ions 194 Electronegativity and Bond Polarity 6.9 Radiation Technologist 174 6.1 6.8 CHEMISTRY LINK TO HEALTH Homes 151 CAREER 6.7 CLINICAL UPDATE Radioisotope 145 5.1 Ionic and Molecular Compounds CLINICAL UPDATE Pharmacy 174 Nuclear Chemistry Improving Crop Production 135 CLINICAL UPDATE Brachytherapy 165 N uclear Fission and Fusion 166 CLINICAL UPDATE Cardiac Imaging Using a Radioisotope 168 Concept Map 168 Chapter Review 169 Key Terms 169 Core Chemistry Skills 170 Understanding the Concepts 170 Additional Practice Problems 171 Challenge Problems 172 Answers 172 CLINICAL UPDATE Improving Crop Production 99 Elements and Symbols 100 The Periodic Table CHEMISTRY LINK TO THE ENVIRONMENT Dating Ancient Objects 161 Medical Applications Using Radioactivity 163 179 182 186 199 Shapes and Polarity of Molecules 202 Intermolecular Forces in Compounds 207 CLINICAL UPDATE Compounds at the Pharmacy 210 Concept Map 210 Chapter Review 211 Key Terms 212 Core Chemistry Skills 212 Understanding the Concepts 214 Additional Practice Problems 215 Challenge Problems 217 Answers 218 Combini ng Ideas from Chapters to 221 Answers 222 190 viii Contents Chemical Reactions and Quantities 223 CAREER The Ideal Gas Law 223 7.2 7.3 Types of Chemical Reactions 230 Oxidation-Reduction Reactions 235 7.4 The Mol e 7.5 Molar Mass 7.6 Calculations Using Molar Mass 7.7 Mole Relationships in Chemical Equations 248 M ass Calculat ions for Chemical Reactions 251 224 238 242 245 Limiting React ants an d Percent Yield 7.10 Energy in Chemi ca l Reacti ons 258 7.9 CHEMISTRY LINK TO HEALTH Hot Packs 261 CLINICAL UPDATE Fitness 262 253 Solutions Cold Packs and Imp roving Natalie's Overall CAREER G ases Using Di alysis for Renal 9.1 Solutions 311 CHEMISTRY LINK TO HEALTH Wat er in the Bod y 312 9.2 Electrolytes and N onelectrolytes 314 CHEMISTRY LINK TO HEALTH Electrolytes in Body Fluids 318 9.3 Solubility 275 319 9.4 Solution Concentrations and Reactions 9.5 Dilution of Solutions 9.6 CAREER Respiratory Therapist 275 8.1 CLINICAL UPDATE Exercise-Induced Asthma 275 Properties of Gases 276 8.2 CHEMISTRY LINK TO HEALTH Measuring Blood Pressure 280 Pressure and Volume (Boyle's Law) 281 CHEMISTRY LINK TO HEALTH Relationship in Breathing 282 8.5 Dialysis Nurse 310 CHEMISTRY LINK TO HEALTH Gout and Kidney Stones: Saturation in Body Fluids 320 8 310 CLINICAL UPDATE Failure 310 Concept Map 263 Chapter Review 263 Key Terms 264 Core Chemistry Skills 265 Understanding the Concepts 267 Additional Practice Problems 269 Challenge Problems 271 Answers 273 Exercise-I nduced Ast hma 301 Concept Map 301 Chapter Review 301 Key Terms 302 Core Chemistry Skills 303 Understanding the Concepts 304 Add itional Practice Problems 305 Challenge Problems 305 Answers 306 Combining Ideas from Chapters and 308 Answers 309 Improving Natalie's Overall Equations for Chemica l Reactions 291 293 CHEMISTRY LINK TO HEALTH Hyperbaric Chambers 296 Partial Pressures (Dalton's Law) 298 CHEMISTRY LINK TO HEALTH Blood Gases 299 CLINICAL UPDATE 7.1 7.8 Volume and Moles (Avogadro's Law) 8.7 8.8 Exercise Physiologist CLINICAL UPDATE Fitness 223 8.6 Pressure-Volume Temperature and Vo lume (Charles' s Law) Temperature and Pressure (Gay-Lussac's Law) 286 The Combined Gas Law 289 284 325 335 Properties of Solutions 338 CHEMISTRY LINK TO HEALTH Dialysis by the Kidneys and the Artif icial Kidney 344 CLINICAL UPDATE Usin g Dialysis f or Renal Failure 346 Concept Map 347 Chapter Review 347 Key Terms 348 Core Chemistry Skills 349 Understanding the Concepts 350 Addit ional Practice Problems 351 Challenge Problems 352 Answers 353 Contents ix Buffers in the Blood 10 CHEMISTRY LINK TO HEALTH Plasma 412 Reaction Rates and Chemical Equilibrium 355 Concept Map 415 Chapter Review 416 Key Terms 417 Key Math Skills 417 Core Chemistry Skills 417 Understanding the Concepts 419 Addit ional Practice Problems 419 Challenge Problems 420 Answers 421 Combining Ideas from Chapters to 11 Answers 425 CAREER CLINICAL UPDATE Acid Reflux Disease 414 Neonatal Nurse 355 CLINICAL UPDATE An Iron-Rich Diet for Children's Anemia 355 10.1 10.2 10.3 10.4 10.5 Rates o f Reactions 356 Chemical Equilibrium Equilibrium Constants 360 363 366 U sing Equi librium Constants Changing Equilibrium Conditions: Le Chate lier's Principle 369 CHEMISTRY LINK TO HEALTH Equilibrium and Hypoxia 372 Oxygen-Hemoglobin CHEMISTRY LINK TO HEALTH Homeostasis: Regulation of Body Temperature 375 CLINICAL UPDATE An Iron-Rich Diet for Children's Anemia 376 Concept Map 377 Chapter Review 377 Key Terms 378 Core Chemistry Skills 378 Understanding the Concepts 379 Additional Practice Problems 379 Challenge Problems 380 Answers 381 11.1 11.2 11.3 11.4 11.5 11.6 12.1 12.2 12.3 12.4 12.5 12.6 382 Acid Reflux Disease 382 383 Strengths o f Acids and Bases Organic Compounds A lkanes 427 430 A lkanes w ith Substituents A lkenes and Alkynes Cis-Trans Isomers 433 438 Properties of Alkanes 441 444 Dissociation o f Water 388 393 395 398 CHEMISTRY LINK TO HEALTH Acid, HCI 404 Cis-Trans Isomers 12.7 Addition Reactions for Alkenes 447 CHEMISTRY LINK TO HEALTH Unsaturated Fats 449 Hydrogenation of 12.8 Aromatic Compounds 453 385 Dissociation o f Weak Acids a nd Bases Stomach 11.7 Reactions of Acids and Bases 405 CHEMISTRY UNK TO HEALTH Antacids 407 11 Buffers 409 Diane's Treatment in the CHEMISTRY LINK TO HEALTH for Night Vision 447 Brensted-Lowry A cids and Ba ses The pH Scale 426 CHEMISTRY LINK TO THE ENVIRONMENT Pheromones in Insect Communication 447 Cl inical Laboratory Technician A cids and Bases Introduction to Organic Chemistry: Hydrocarbons CLINICAL UPDATE Burn Unit 426 Acids and Bases 382 CLINICAL UPDATE 12 CAREER Firefighter/ Emergency Medical Technician 426 11 CAREER 424 CHEMISTRY LINK TO HEALTH Aromatic Compounds 455 Some Common CHEMISTRY LINK TO HEALTH Hydrocarbons (PAHs) 456 Polycyclic Aromatic CLINICAL UPDATE Burn Unit 456 Diane's Treatment in the Concept Map 457 Chapter Review 458 Summary of Naming 459 Summary of Reactions 459 208 CHAPTER Ionic and Molecular Compounds Ionic compounds have high melting points For example, solid NaCI melts at 801 °C Large amounts of energy are needed to overcome the strong intermolecular forces between positive and negative ions In solids containing molecules with covalent bonds, there are intermolecular forces too, but they are weaker than those of an ionic compound Dipole- Dipole Attractions T For polar molecules, intermolecular forces cal led dipole-dipole a ttractions occur between the positive end of one molecule and the negative end of another For a polar molecule with a dipole such as HCI, the partially positive H atom of one HCI molecule attracts the partially negative Cl atom in another HCI molecule Dipole-dipole attraction Hydrogen Bonds Polar molecules containing hydrogen atoms bonded to highly electronegative atoms of nitrogen , oxygen, or fluorine form especially strong dipole-dipole attractions This type of attraction, called a hydrogen bon d, occurs between the partially positive hydrogen atom in one molecule and the partially negative fluorine, oxygen, or nitrogen atom in another molecule Hydrogen bonds are the strongest type of intermolecular forces between polar covalent molecules They are a major factor in the formation and structure of biological molecules such as proteins and DNA ·r· Hydrogen bond Dispersion Forces S" Very weak attractions called dispersion forces are the only intermolecular forces that occur between nonpolar molecules Usually, the electrons in a nonpolar covalent molecule are distributed symmetrically However, the movement of the electrons may place more of them in one part of the molecule than another, which forms a temporary dipole These momentary dipoles align the molecules so that the positive end of one molecule is attracted to the negative end of another molecule Although dispersion forces are very weak, they make it possible for nonpolar molecules to form liquids and solids · r· H ydrogen bond TABLE 6.18 Melting Points of Selected Substances Ionic Bonds MgF2 1248 Nact 801 ( ) Temporary dipoles 0.~_:P·- u ,u Symmetrical distribution Nucleus U nsymmctrica) distributjon Dispersion force.~ Nonpolar covalent molecules have weak attractions when they form t e mporary dipoles Hydrogen Bonds H20 N H3 - 78 Dipole-Dipole Attractions HI - 51 HBr -89 HCI - 115 Dispersio n Forces Br2 - Cl2 - 101 F2 - 220 Intermolecular Forces and Melting Points The melting point of a substance is related to the strength of the intermolecular forces between its particles A compound wi th weak intermolecular forces, such as dispersion forces, has a low melting point because only a small amount of energy is needed to separate the molecules and form a liquid A compound with dipole-dipole attractions requires more energy to break the intermolecular forces between the molecules A compound that can form hydrogen bonds requires even more energy to overcome the intermolecular forces that exist between its molecu les Larger amounts of energy are needed to overcome the strong intermolecular forces between positive and negative ions and to melt an ionic solid TABLE 18 compares the melting points of some substances with various kinds of intermolecular forces The various types of attractions between particles in solids and liquids are summarized in TABLE 19 6.9 Int ermolecular Forces in Compounds Between Atom s or Ions 209 Strong Ionic bonds Covalent bonds (X = nonmetal) CI - CI Between M olecul es Hydrogen bonds (X=N, O,orF) Jji" 1)a+ H-F ···H -F Dipole-dipole attractions (X and Y = nonmetals) Dispersion forces (temporary shift of electrons in nonpolar bonds) (temporary dipoles) {); a;- tr F-F · ··F-F Weak ,.SAMPLE PROBLEM 6.19 Int ermolecula r Forces Betwee n Pa rticles Indicate the m:Yor type of intermolecular forces-dipole-dipole attractions, hydrogen bonds, or dispersion forces-expected of each of the following: a HF b Br2 c PCI3 SOLUTION a hydrogen bonds b dispersion forces c dipole-dipole attractions STUDY CHECK 6.19 Indicate the major type of intermolecular forces in each of the following: a H2S b H20 ANSWER a dipole~ipole attractions b hydrogen bonds Try Practice Problems 6.87 to 6.92 PRACTICE PROBLEMS 6.9 Intermolecular Forces in Compounds 6.87 Identify the major type of intermolecular forces between the particles of each of the following: a BrF b KCI c NF3 d CI2 6.89 Identify the strongest intennolecular forces between the particles of each of the following: a CH30H b CO c CF4 d CH3 CH3 6.88 Identify the major type of intermolecular forces between the particles of each of the following: a HCI b MgF2 c PBr3 d NH3 6.90 Identify the strongest intem10lecular forces between the particles of each of the following: a b Sil-l c CH3CI d H20 210 CHAPTER Ionic and Molecular Compounds 6.91 Identify the substance in each of the following pairs that would have the higher melting point and explain your choice: a HF or HBr b HF or NaF d CJ-L or CH3 H c MgBr2 or PBr3 CLINICAL UPDATE 6.92 Identify the substance in each of the following pairs that would have the higher melting point and explain your choice: a NaCl or HCl b H 20 or H2Se c NH or PH d F2 or HF Compounds at the Pharmacy Richard returns to the pharmacy to pick up aspirin, C9Hs0 , and acetam inophen, CsH9N02 He talks to Sarah about a way to t reat his sore toe Sarah recommends soaking his foot in a solution of Epsom salts, which is magnesium sulfate Richard also asks Sarah to recommend an ant acid for his upset stomach and an iron supplement Sarah suggests an antacid that contains calcium carbonate and alum inum hydroxide, and iron(ll) sulfate as an iro n supp lement Richard also picks up toothpaste containing tin(ll) fluoride, and carbonated water, which contains carbon d ioxide Clinical Applications 6.93 Using the electronegativity values in Figure 6.6, calculate the electronegativity difference for the bond between each of the following pairs of atoms present in aspirin: a C and C b C and H c C and 6.94 Using the electronegativity values in Figure 6.6, calculate the electronegativity difference for the bond between each of the following pairs of atoms present in acetaminophen: a C and N b N and H c H and 6.95 Classify each of the bonds in problem 6.93 as ionic, polar covalent, or nonpolar covalent 6.96 Classify each of the bonds in problem 6.94 as ionic, polar covalent, or nonpolar CONCEPT MAP , -[.JM!i-'~I·Jh[.]'iSII!-';«·]&14·11!~1.}-. _ ., ( I I contain Ionic Bonds ) ' r ~ ( be~een + N-o_n_m_e_t_a-ls .,) (, -M - e_ta_l_s - ,) (. that ~orm + that form + Positive Ions ( Charge Balance to write Molecular Compounds contain + ( l~ ( Ionic Compounds ) J subs~ripts for the + Covalent Bonds ) I have ) + Intermolecular Forces between ( + Nonmetals called ) + Dipole-Dipole Attractions, Hydrogen Bonds, or Dispersion Forces Chapter Review I 211 CHAPTER REVIEW 6.1 Ions: Transfer of Electrons M~· ~~~ : LEARNING GOAL Write the symbols for the simple ions of the repre sentative e lements Transferor e lectrons • T he s tability of the noble gases is associated with a stable e lectron configuration in the outermost energy level • With the exception o f helium, which has two e lectrons, noble gases have eight valence electrons, which is an octet Ionic bond • Ato ms of e lements in Groups I A to A (I, 2, 13 to 17) achieve stability by losing, gaining, or sharing their valence electrons in the formation of compound~ • Metals of the representative e le ments lose valence e lectrons to form positively charged ions (cations): Groups IA ( I), I+, 2A (2), +, and 3A (13), + • When reacting with metals, nonmetals gain electrons to form octets and fo rm negatively charged ions (anions): Groups 5A( J5),3 -, 6A(I6),2- ,and7A( J7), 1- • The ammonium ion, NH +, is a positive polyatomic ion • When more than one polyato mic ion is used for charge balance, parentheses enclose the form ula o f the polyatomic ion 6.5 Molecular Compounds: Sharing Electrons LEARNING GOAL Give n the formula of a I mono molecular compound , write its correct name; di g iven the name of a molecula r comp ound, write its formula tri • In a covalent bond, atoms o f nonmetals share tetra valence electrons such that each ato m ha~ a penta stable electron configuration • The first nonmetal in a molecular compound uses its e le ment name; the second nonmetal uses the first syllable of its element name followed by ide • The name of a mo lecular compound with two different atoms uses prefixes to indicate the subscripts in the form ula 6.6 Lewis Structures for Molecules and Polyatomic Ions 6.2 Ionic Compounds LEARNING GOAL Draw the l e wis structure s fo r LEARNING GOAL Using cha rge balance, write molecular comp ounds and polyatomic ions :c1: • The total number of valence e lectrons is determined for al l the atoms in the molecule or polyato mic ion • Any negative charge is added to the total valence electrons, wherea~ any positive charge is subtracted • In the Lewis structure, a bonding pair o f electrons is placed between the central atom and each of the attached atoms • Any remaining valence electrons are used as lone pairs to complete the octets of the surrounding atoms and then the central atom • If octets are not completed, one or more lone pairs of electrons are placed a~ bonding pairs forming double or triple bonds the correct fo rmula for an ionic compound • T he total positive and negative ionic charge is balanced in the fo rmula of an ionic compound • C harge balance in a formula is achieved by using s ubscripts after each symbol so that the overall charge is zero 6.3 Naming and Writing Ionic Formulas LEARNING GOAL Given the formula of an ionic comp ound, write the corre ct name; given ' "~ : ~ ! · ~