Preview Chemistry an introduction to general, organic, and biological chemistry, 12th Edition by Karen C. Timberlake (2015)

Preview Chemistry an introduction to general, organic, and biological chemistry, 12th Edition by Karen C. Timberlake (2015) Preview Chemistry an introduction to general, organic, and biological chemistry, 12th Edition by Karen C. Timberlake (2015) Preview Chemistry an introduction to general, organic, and biological chemistry, 12th Edition by Karen C. Timberlake (2015) Preview Chemistry an introduction to general, organic, and biological chemistry, 12th Edition by Karen C. Timberlake (2015)

Periodic Table of Elements Representative elements Halogens Noble gases Alkali Alkaline metals earth metals Period number Group 1A 1 H 1.008 3 Li 13 14 15 16 17 Group Group Group Group Group 3A 4A 5A 6A 7A Group 2A Be 6.941 9.012 11 12 22.99 24.31 19 3B 4B 5B 6B 7B 20 21 22 Ti 23 V 24 25 39.10 40.08 44.96 47.87 50.94 52.00 37 38 39 40 41 Na Mg K B Transition elements Ca Sc 8B 10 26 27 54.94 55.85 42 43 C N O 18 Group 8A He 4.003 10 10.81 12.01 14.01 16.00 19.00 F Ne 13 Al 14 Si 15 16 S 17 Cl 18 Ar 26.98 28.09 30.97 32.07 35.45 39.95 34 35 36 20.18 11 1B 12 2B 28 29 30 31 32 33 Se Br Kr 58.93 58.69 63.55 65.41 69.72 72.64 74.92 78.96 79.90 83.80 44 45 46 47 48 49 50 51 52 53 54 P Cr Mn Fe Co Ni Cu Zn Ga Ge As Rb Sr Y Zr Nb Mo Tc Sn Sb Te I Xe 87.62 88.91 91.22 92.91 95.94 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 55 56 57* 72 Ta 74 W 75 76 Re Os 77 Ir 78 Pt 79 80 Au Hg 81 Tl 82 Pb 83 Bi 84 85 86 132.9 137.3 138.9 Hf 73 1992 Ru Rh Pd Ag Cd 85.47 178.5 180.9 183.8 186.2 190.2 192.2 195.1 197.0 200.6 204.4 87 88 89† 104 105 106 107 108 109 110 111 112 113 207.2 114 209.0 115 12092 116 12102 117 12222 118 12262 12272 12612 12622 12662 12642 12652 12682 12712 12722 12852 12842 12892 12882 12932 12932 12942 58 59 60 61 62 63 64 65 66 67 68 69 70 71 140.1 140.9 144.2 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0 91 92 11452 150.4 90 93 94 95 96 97 98 99 100 101 102 103 232.0 231.0 12372 12442 12432 12472 12472 12522 12572 12582 12592 12622 Cs Ba Fr 12232 La Ra Ac Rf Db Sg Bh Hs Mt Ds Rg Cn — *Lanthanides †Actinides Metals In Ce — Lv — Rn — Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa Metalloids Fl Po At U 238.0 Np Pu Am Cm Bk Nonmetals Cf 12512 Es Fm Md No Lr Atomic Masses of the Elements Name Actinium Aluminum Americium Antimony Argon Arsenic Astatine Barium Berkelium Beryllium Bismuth Bohrium Boron Bromine Cadmium Calcium Californium Carbon Cerium Cesium Chlorine Chromium Cobalt Copernicium Copper Curium Darmstadtium Dubnium Dysprosium Einsteinium Erbium Europium Fermium Flerovium Fluorine Francium Gadolinium Gallium Germanium Gold Hafnium Hassium Helium Holmium Hydrogen Indium Iodine Iridium Iron Krypton Lanthanum Lawrencium Lead Lithium Livermorium Lutetium Magnesium Manganese Meitnerium a Symbol Ac Al Am Sb Ar As At Ba Bk Be Bi Bh B Br Cd Ca Cf C Ce Cs Cl Cr Co Cn Cu Cm Ds Db Dy Es Er Eu Fm Fl F Fr Gd Ga Ge Au Hf Hs He Ho H In I Ir Fe Kr La Lr Pb Li Lv Lu Mg Mn Mt Atomic Number Atomic Massa 89 13 95 51 18 33 85 56 97 83 107 35 48 20 98 58 55 17 24 27 112 29 96 110 105 66 99 68 63 100 114 87 64 31 32 79 72 108 67 49 53 77 26 36 57 103 82 116 71 12 25 109 12272 26.98 12432 121.8 39.95 74.92 12102 137.3 12472 9.012 209.0 12642 10.81 79.90 112.4 40.08 12512 12.01 140.1 132.9 35.45 52.00 58.93 12852 63.55 12472 12712 12622 162.5 12522 167.3 152.0 12572 12892 19.00 12232 157.3 69.72 72.64 197.0 178.5 12652 4.003 164.9 1.008 114.8 126.9 192.2 55.85 83.80 138.9 12622 207.2 6.941 12932 175.0 24.31 54.94 12682 b Name Mendelevium Mercury Molybdenum Neodymium Neon Neptunium Nickel Niobium Nitrogen Nobelium Osmium Oxygen Palladium Phosphorus Platinum Plutonium Polonium Potassium Praseodymium Promethium Protactinium Radium Radon Rhenium Rhodium Roentgenium Rubidium Ruthenium Rutherfordium Samarium Scandium Seaborgium Selenium Silicon Silver Sodium Strontium Sulfur Tantalum Technetium Tellurium Terbium Thallium Thorium Thulium Tin Titanium Tungsten Uranium Vanadium Xenon Ytterbium Yttrium Zinc Zirconium — — — — Values for atomic masses are given to four significant figures Values in parentheses are the mass number of an important radioactive isotope b Symbol Atomic Number Atomic Massa Md Hg Mo Nd Ne Np Ni Nb N No Os O Pd P Pt Pu Po K Pr Pm Pa Ra Rn Re Rh Rg Rb Ru Rf Sm Sc Sg Se Si Ag Na Sr S Ta Tc Te Tb Tl Th Tm Sn Ti W U V Xe Yb Y Zn Zr — — — — 101 80 42 60 10 93 28 41 102 76 46 15 78 94 84 19 59 61 91 88 86 75 45 111 37 44 104 62 21 106 34 14 47 11 38 16 73 43 52 65 81 90 69 50 22 74 92 23 54 70 39 30 40 113 115 117 118 12582 200.6 95.94 144.2 20.18 12372 58.69 92.91 14.01 12592 190.2 16.00 106.4 30.97 195.1 12442 12092 39.10 140.9 11452 231.0 12262 12222 186.2 102.9 12722 85.47 101.1 12612 150.4 44.96 12662 78.96 28.09 107.9 22.99 87.62 32.07 180.9 1992 127.6 158.9 204.4 232.0 168.9 118.7 47.87 183.8 238.0 50.94 131.3 173.0 88.91 65.41 91.22 12842 12882 12932 12942 Chemistry An Introduction to General, Organic, and Biological Chemistry Twelfth Edition Karen C Timberlake Boston Columbus Indianapolis New York San Francisco Upper Saddle River Amsterdam Cape Town Dubai London Madrid Milan Munich Paris Montréal Toronto Delhi Mexico City São Paulo Sydney Hong Kong Seoul Singapore Taipei Tokyo Editor in Chief: Adam Jaworski Executive Editor: Jeanne Zalesky Executive Marketing Manager: Jonathan Cottrell Project Editor: Jessica Moro Assistant Editor: Lisa R Pierce Associate Media Producer: Jackie Jakob Supervising Project Manager, Instructor Media: Shannon Kong Editorial Assistant: Lisa Tarabokjia Marketing Assistant: Nicola Houston Managing Editor, Chemistry: Gina M Cheselka Project Manager: Wendy A Perez Full Service >Compositor: PreMediaGlobal Full Service Project Manager: Andrea Stefanowicz Illustrations: Imagineering Design Manager: Mark Ong Interior Designer: Jerilyn Bockorick Cover Designer: Richard Leeds Photo Manager: Maya Melenchuk Photo Researcher: Erica Gordon, Q2A >Bill Smith Manager, Rights and Permissions: Timothy Nicholls Associate Project Manager, Rights and Permissions: Michael V Farmer Text Permissions Research: PreMediaGlobal Operations Specialist: Christy Hall Cover Photo Credit: Fer Gregory >Shutterstock Credits and acknowledgments borrowed from other sources and reproduced, with permission, in this textbook appear on p C-1 Copyright © 2015, 2012, 2009, 2006, 2003, 1999, 1996, 1992, 1988, 1983, 1979, 1976 by Pearson Education, Inc All rights reserved Manufactured in the United States of America This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means; electronic, mechanical, photocopying, recording, or likewise To obtain permission1s2 to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, Lake Street, Department 1G, Upper Saddle River, NJ 07458 Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks Where those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed in initial caps or all caps Library of Congress Cataloging-in-Publication Data Timberlake, Karen C., author  Chemistry: an introduction to general, organic, and biological chemistry.—Twelfth edition >Karen C Timberlake    pages cm   ISBN-13: 978-0-321-90844-5   ISBN-10: 0-321-90844-9   Chemistry—Textbooks I Title   QD31.3.T55 2015  540—dc23 2013026126 10—CRK—18 17 16 15 14 www.pearsonhighered.com ISBN-10: 0-321-90844-9 ISBN-13: 978-0-321-90844-5 Brief Contents Chemistry in Our Lives 1 Chemistry and Measurements 23 Matter and Energy 57 Atoms and Elements 95 Nuclear Chemistry 134 Ionic and Molecular Compounds 165 Chemical Quantities and Reactions 211 Gases 254 Solutions 281 10 Acids and Bases and Equilibrium 322 11 Introduction to Organic Chemistry: Hydrocarbons 360 12 Alcohols, Thiols, Ethers, Aldehydes, and Ketones 398 13 Carbohydrates 433 14 Carboxylic Acids, Esters, Amines, and Amides 472 15 Lipids 511 16 Amino Acids, Proteins, and Enzymes 551 17 Nucleic Acids and Protein Synthesis 590 18 Metabolic Pathways and Energy Production 622  iii Contents Chemistry Link to Health  Toxicology and Risk–Benefit Assessment 41 Chemistry in Our Lives 1 Career: Forensic Scientist 1 1.1 Chemistry and Chemicals 2 1.2 Scientific Method: Thinking Like a Scientist 4 Chemistry Link to Health  Early Chemist: Paracelsus 4 1.3 Learning Chemistry: A Study Plan 6 1.4 Key Math Skills for Chemistry 9 Guide to Problem Solving  Writing a Number in Scientific Notation 16 2.6 Problem Solving Using Unit Conversion 41 Guide to Problem Solving  Using Conversion Factors 42 2.7 Density 45 Explore Your World  Sink or Float 46 Chemistry Link to Health  Bone Density 47 Guide to Problem Solving  Using Density 48 Concept Map  49 Chapter Review  50 Key Terms  50 Core Chemistry Skills  51 Understanding the Concepts  52 Additional Questions and Problems  53 Challenge Questions  54 Answers 55 Concept Map  18 Chapter Review  18 Key Terms  18 Key Math Skills  19 Understanding the Concepts  20 Additional Questions and Problems  20 Challenge Questions  21 Answers 22 Matter and Energy 57 Career: Dietitian 57 3.1 Classification of Matter 58 Chemistry and Measurements 23 Career: Registered Nurse 23 2.1 Units of Measurement 24 Explore Your World  Units Listed on Labels 27 2.2 2.3 2.4 2.5 Measured Numbers and Significant Figures 28 Significant Figures in Calculations 30 Prefixes and Equalities 33 Writing Conversion Factors 37 Explore Your World  SI and Metric Equalities on Product Labels 38 iv Chemistry Link to Health  Breathing Mixtures 61 3.2 States and Properties of Matter 62 3.3 Temperature 64 Guide to Problem Solving  Calculating Temperature 66 Chemistry Link to Health  Variation in Body Temperature 67 3.4 Energy 68 Chemistry Link to the Environment Carbon Dioxide and Climate Change 70 3.5 Energy and Nutrition 70 Guide to Problem Solving  Calculating the Energy from a Food 72 Explore Your World  Counting Calories 72 Chemistry Link to Health  Losing and Gaining Weight 72 3.6 Specific Heat 73 Contents  v Guide to Problem Solving  Calculations Using Specific Heat 75 3.7 Changes of State 75 Guide to Problem Solving  Calculations Using a Heat Conversion Factor 77 Chemistry Link to Health  Steam Burns 80 Concept Map  84 Chapter Review  85 Key Terms  86 Core Chemistry Skills  86 Understanding the Concepts  87 Additional Questions and Problems  89 Challenge Questions  90 Answers 91 Combining Ideas from Chapters to 3 93 Nuclear Chemistry 134 Career: Radiation Technologist 134 5.1 Natural Radioactivity 135 5.2 Nuclear Reactions 139 Guide to Problem Solving  Completing a Nuclear Equation 140 Chemistry Link to the Environment Radon in Our Homes 140 5.3 Radiation Measurement 145 Atoms and Elements 95 Career: Farmer 95 4.1 Elements and Symbols 96 Chemistry Link to the Environment Many Forms of Carbon 98 Chemistry Link to Health  Toxicity of Mercury 99 4.2 The Periodic Table 99 Chemistry Link to Health  Elements Essential to Health 103 4.3 The Atom 105 Explore Your World  Repulsion and Attraction 108 4.4 Atomic Number and Mass Number 108 4.5 Isotopes and Atomic Mass 111 4.6 Electron Energy Levels 115 Chemistry Link to the Environment EnergySaving Fluorescent Bulbs 117 Chemistry Link to Health  Biological Reactions to UV Light 119 4.7 Trends in Periodic Properties 119 Concept Map  126 Chapter Review  126 Key Terms  127 Core Chemistry Skills  128 Understanding the Concepts  129 Additional Questions and Problems  130 Challenge Questions  131 Answers 132 Chemistry Link to Health  Radiation and Food 146 5.4 Half-Life of a Radioisotope 148 Guide to Problem Solving  Using Half-Lives 149 Chemistry Link to the Environment Dating Ancient Objects 150 5.5 Medical Applications Using Radioactivity 152 Chemistry Link to Health Brachytherapy 154 5.6 Nuclear Fission and Fusion 155 Chemistry Link to the Environment Nuclear Power Plants 158 Concept Map  159 Chapter Review  159 Key Terms  160 Core Chemistry Skills  160 Understanding the Concepts  161 Additional Questions and Problems  161 Challenge Questions  162 Answers 163 Ionic and Molecular Compounds 165 Career: Pharmacy Technician 165 6.1 Ions: Transfer of Electrons 166 Chemistry Link to Health  Some Important Ions in the Body 170 6.2 Writing Formulas for Ionic Compounds 171 6.3 Naming Ionic Compounds 173 vi Contents Guide to Problem Solving  Naming Ionic Compounds with Metals That Form a Single Ion 174 Guide to Problem Solving  Naming Ionic Compounds with Variable Charge Metals 175 Guide to Problem Solving  Writing Formulas from the Name of an Ionic Compound 176 6.4 Polyatomic Ions 177 Guide to Problem Solving  Writing Formulas with Polyatomic Ions 179 Guide to Problem Solving  Naming Ionic Compounds with Polyatomic Ions 180 6.5 Molecular Compounds: Sharing Electrons 182 Guide to Problem Solving  Drawing ElectronDot Formulas 185 Guide to Problem Solving  Naming Molecular Compounds 186 Guide to Problem Solving  Writing Formulas for Molecular Compounds 187 6.6 Electronegativity and Bond Polarity 189 6.7 Shapes and Polarity of Molecules 191 Guide to Problem Solving  Predicting Molecular Shape 1VSEPR Theory2 194 Guide to Problem Solving  Determination of Polarity of a Molecule 196 6.8 Attractive Forces in Compounds 197 Chemistry Link to Health  Attractive Forces in Biological Compounds 198 Concept Map  200 Chapter Review  201 Key Terms  202 Core Chemistry Skills  202 Understanding the Concepts  204 Additional Questions and Problems  205 Challenge Questions  206 Answers 207 7.2 Molar Mass and Calculations 216 Guide to Problem Solving  Calculating Molar Mass 217 Explore Your World  Calculating Moles in the Kitchen 218 Guide to Problem Solving  Calculating the Moles 1or Grams2 of a Substance from Grams 1or Moles2 219 7.3 Equations for Chemical Reactions 221 Guide to Problem Solving  Balancing a Chemical Equation 224 7.4 Types of Reactions 227 Chemistry Link to Health Incomplete Combustion: Toxicity of Carbon Monoxide 231 7.5 Oxidation–Reduction Reactions 232 Explore Your World  Oxidation of Fruits and Vegetables 234 7.6 Mole Relationships in Chemical Equations 235 Guide to Problem Solving  Calculating the Quantities of Reactants and Products in a Chemical Reaction 237 7.7 Mass Calculations for Reactions 238 7.8 Energy in Chemical Reactions 240 Chemistry Link to Health  Cold Packs and Hot Packs 241 Concept Map  243 Chapter Review  244 Key Terms  245 Core Chemistry Skills  245 Understanding the Concepts  247 Additional Questions and Problems  249 Challenge Questions  250 Answers 251 Combining Ideas from Chapters to 6 209 Chemical Quantities and Reactions 211 Career: Exercise Physiologist 211 7.1 The Mole 212 Guide to Problem Solving  Calculating the Atoms or Molecules of a Substance 214 Guide to Problem Solving  Calculating the Moles of an Element in a Compound 215 Gases 254 Career: Respiratory Therapist 254 8.1 Properties of Gases 255 Explore Your World  Forming a Gas 257 Chemistry Link to Health  Measuring Blood Pressure 260 8.2 Pressure and Volume 1Boyle’s Law2 261 Guide to Problem Solving  Using the Gas Laws 262 Chemistry Link to Health Pressure–Volume Relationship in Breathing 262 Contents  8.3 8.4 8.5 8.6 Temperature and Volume 1Charles’s Law2 264 Temperature and Pressure 1Gay-Lussac’s Law2 266 The Combined Gas Law 267 Volume and Moles 1Avogadro’s Law2 269 Guide to Problem Solving  Using Molar Volume 271 8.7 Partial Pressures 1Dalton’s Law2 272 Guide to Problem Solving  Calculating Partial Pressure 273 Chemistry Link to Health  Blood Gases 273 Chemistry Link to Health Hyperbaric Chambers 274 Concept Map  275 Chapter Review  276 Key Terms  277 Core Chemistry Skills  277 Understanding the Concepts  278 Additional Questions and Problems  279 Challenge Questions  279 Answers 280 vii 9.6 Properties of Solutions 305 Chemistry Link to Health  Colloids and Solutions in the Body 306 Explore Your World  Everyday Osmosis 307 Chemistry Link to Health  Dialysis by the Kidneys and the Artificial Kidney 310 Concept Map  312 Chapter Review  312 Key Terms  313 Core Chemistry Skills  314 Understanding the Concepts  314 Additional Questions and Problems  315 Challenge Questions  316 Answers 317 Combining Ideas from Chapters to 9 319 10 Acids and Bases and Equilibrium 322 Solutions 281 Career: Dialysis Nurse 281 9.1 Solutions 282 Chemistry Link to Health  Water in the Body 284 Explore Your World  Like Dissolves Like 285 9.2 Electrolytes and Nonelectrolytes 286 Chemistry Link to Health  Electrolytes in Body Fluids 289 9.3 Solubility 290 Chemistry Link to Health  Gout and Kidney Stones: A Problem of Saturation in Body Fluids 292 Explore Your World  Preparing Rock Candy 293 Explore Your World  Preparing Solutions 293 9.4 Concentrations of Solutions 295 Guide to Problem Solving  Calculating Solution Concentration 296 Guide to Problem Solving  Using Concentration to Calculate Mass or Volume 300 9.5 Dilution of Solutions 302 Guide to Problem Solving  Calculating Dilution Quantities 303 Career: Clinical Laboratory Technician 322 10.1 Acids and Bases 323 Guide to Problem Solving  Writing Conjugate Acid–Base Pairs 327 10.2 Strengths of Acids and Bases 328 10.3 Acid–Base Equilibrium 332 Chemistry Link to Health Oxygen– Hemoglobin Equilibrium and Hypoxia 334 10.4 Ionization of Water 336 Guide to Problem Solving  Calculating 3H3O + and 3OH - in Aqueous Solutions 337 10.5 The pH Scale 338 Guide to Problem Solving  Calculating pH of an Aqueous Solution 341 Explore Your World  Using Vegetables and Flowers as pH Indicators 342 Guide to Problem Solving  Calculating 3H3O + from pH 342 Chemistry Link to Health  Stomach Acid, HCl 344 10.6 Reactions of Acids and Bases 345 Guide to Problem Solving  Balancing an Equation for Neutralization 346 Guide to Problem Solving  Calculations for an Acid–Base Titration 347 Chemistry Link to Health Antacids 348 4.7  Trends in Periodic Properties  119 Chemistry Link to Health Biological Reactions to UV Light Our everyday life depends on sunlight, but exposure to sunlight can have damaging effects on living cells, and too much exposure can even cause their death The light energy, especially ultraviolet 1UV2, excites electrons and may lead to unwanted chemical reactions The list of damaging effects of sunlight includes sunburn; wrinkling; premature aging of the skin; changes in the DNA of the cells, which can lead to skin cancers; inflammation of the eyes; and perhaps cataracts Some drugs, like the acne medications Accutane and Retin-A, as well as antibiotics, diuretics, sulfonamides, and estrogen, make the skin extremely sensitive to light However, medicine does take advantage of the beneficial effect of sunlight Phototherapy can be used to treat certain skin conditions, including psoriasis, eczema, and dermatitis In the treatment of psoriasis, for example, oral drugs are given to make the skin more photosensitive; exposure to UV follows Low-energy light is used to break down bilirubin in neonatal jaundice Sunlight is also a factor in stimulating the immune system Babies with neonatal jaundice are treated with UV light In a disorder called seasonal affective disorder or SAD, people experience mood swings and depression during the winter Some research suggests that SAD is the result of a decrease of serotonin, or an increase in melatonin, when there are fewer hours of sunlight One treatment for SAD is therapy using bright light provided by a lamp called a light box A daily exposure to intense light for 30 to 60 seems to reduce symptoms of SAD Questions and Problems 4.6 Electron Energy Levels Learning Goal  Given the name or symbol of one of the first 20 elements in the periodic table, write the electron arrangement 4.39 Electrons can move to higher energy levels when they _ 1absorb > emit2 energy 4.40 Electrons drop to lower energy levels when they _ 1absorb > emit2 energy 4.41 Identify the form of electromagnetic radiation in each pair that has the greater energy: a green light or yellow light b.  microwaves or blue light 4.42 Identify the form of electromagnetic radiation in each pair that has the greater energy: a radio waves or violet light b infrared light or ultraviolet light 4.43 Write the electron arrangement for each of the following elements: 1Example: sodium 2,8,12 a carbon b argon c potassium d silicon e helium f nitrogen 4.44 Write the electron arrangement for each of the following elements: 1Example: sodium 2,8,12 a phosphorus b neon c sulfur d magnesium e aluminum f fluorine 4.45 Identify the elements that have the following electron arrangements: Energy Level a b c d e 4.46 Identify the elements that have the following electron arrangements: Energy Level a b c d 8 e 4.7  Trends in Periodic Properties Learning Goal The electron arrangements of atoms are an important factor in the physical and chemical properties of the elements Now we will look at the valence electrons in atoms, the trends in atomic size, ionization energy, and metallic character Known as periodic properties, there is a pattern of regular change going across a period, and then the trend is repeated again in each successive period Use the electron arrangement of elements to explain the trends in periodic properties 120  Chapter 4  Atoms and Elements Core Chemistry Skill Identifying Trends in Periodic Properties Group Number and Valence Electrons The chemical properties of representative elements in Groups 1A 112 to 8A 1182 are mostly due to the valence electrons, which are the electrons in the outermost energy level The group number gives the number of valence electrons for each group of representative elements For example, all the elements in Group 1A 112 have one valence electron All the elements in Group 2A 122 have two valence electrons The halogens in Group 7A 1172 all have seven valence electrons Table 4.10 shows how the number of valence electrons for common representative elements is consistent with the group number Table 4.10  Comparison of Electron Arrangements, by Group, for Some Representative Elements Number of Electrons in Energy Level Group Number Element Symbol 1A 112 Lithium Li Sodium Na Potassium K 8 2A 122 Beryllium Be 2 Magnesium Mg Calcium Ca 8 3A 1132 Boron B Aluminum Al Gallium Ga 18 4A 1142 Carbon C Silicon Si Germanium Ge 18 5A 1152 Nitrogen N Phosphorus P Arsenic As 18 6A 1162 Oxygen O Sulfur S Selenium Se 18 7A 1172 Fluorine F Chlorine Cl Bromine Br 18 8A 1182 Helium He Neon Ne Argon Ar 8 Krypton Kr 18 4 Sample Problem 4.11 Using Group Numbers Using the periodic table, write the group number and the number of valence electrons for each of the following elements: a cesium b iodine Solution a Cesium 1Cs2 is in Group 1A 112; cesium has one valence electron b Iodine 1I2 is in Group 7A 1172; iodine has seven valence electrons Study Check 4.11 What is the group number of elements with atoms that have five valence electrons? 4.7  Trends in Periodic Properties  121 Number of Valence Electrons Increases Table 4.11  Electron-Dot Symbols for Selected Elements in Periods 1–4 Group Number 1A 112 Number of Valence Electrons 2A 122 3A 1132 4A 142 5A 1152 6A 1162 7A 1172 8A 1182 Electron-Dot Symbol He * H Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ga Ge As Se Br Kr *Helium 1He2 is stable with two valence electrons Electron-Dot Symbols Core Chemistry Skill An electron-dot symbol, also known as a Lewis structure, represents the valence electrons as dots that are placed on the sides, top, or bottom of the symbol for the element One to four valence electrons are arranged as single dots When an atom has five to eight valence electrons, one or more electrons are paired Any of the following would be an acceptable electron-dot symbol for magnesium, which has two valence electrons: Drawing Electron-Dot Symbols Electron-dot symbols for magnesium Mg Mg Mg Mg Mg Mg Electron-dot symbols for selected elements are given in Table 4.11 Sample Problem 4.12 Drawing Electron-Dot Symbols Draw the electron-dot symbol for each of the following: a bromine Atoms of magnesium b aluminum Solution a Because the group number for bromine is 7A 1172, bromine has seven valence electrons, which are drawn as seven dots, three pairs and one single dot, around the symbol Br Br b Aluminum, in Group 3A 1132, has three valence electrons, which are shown as three single dots around the symbol Al Al Study Check 4.12 What is the electron-dot symbol for phosphorus? Atomic Size The size of an atom is determined by the distance of the valence electrons from the nucleus For each group of representative elements, the atomic size increases going from the top to the bottom because the outermost electrons in each energy level are farther from the nucleus For example, in Group 1A 112, Li has a valence electron in energy level 2; Na has a valence electron in energy level 3; and K has a valence electron in energy level This means that a K atom is larger than a Na atom, and a Na atom is larger than a Li atom 1see Figure 4.132 Mg Electron-dot symbol Electron arrangement 2,8, Magnesium 1Mg2 has two valence electrons, which give it an electron-dot symbol with two dots 122  Chapter 4  Atoms and Elements Figure 4.13  N  For representative elements, the atomic size increases going down a group but decreases going from left to right across a period Q Why does the atomic size increase going down a group of representative elements? Atomic Size Decreases 1A 112 2A 122 3A 1132 Groups 4A 5A 1142 1152 6A 1162 7A 1172 H 8A 1182 He Atomic Size Increases Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Ga Ge As Se Br Kr Rb Sr In Sn Sb Te I Xe For the elements in a period, an increase in the number of protons in the nucleus increases the attraction for the outermost electrons As a result, the outer electrons are pulled closer to the nucleus, which means that the size of representative elements decreases going from left to right across a period Sample Problem 4.13  Size of Atoms Identify the smaller atom in each of the following pairs and explain your choice: a N or F b K or Kr c Ca and Sr Ionization Energy Decreases Solution a The F atom has a greater positive charge on the nucleus, which pulls electrons closer, and makes the F atom smaller than the N atom Atomic size decreases going from left to right across a period b The Kr atom has a greater positive charge on the nucleus, which pulls electrons closer, and makes the Kr atom smaller than the K atom Atomic size decreases going from left to right across a period c The outer electrons in the Ca atom are closer to the nucleus than in the Sr atom, which makes the Ca atom smaller than the Sr atom Atomic size increases going down a group Li atom Na atom Study Check 4.13 Distance between the nucleus and valence electron K atom As the distance from the nucleus to the valence electrons increases in Group 1A 112, the ionization energy decreases Which atom has the largest atomic size, Mg, Ca, or Cl? Ionization Energy In an atom, negatively charged electrons are attracted to the positive charge of the protons in the nucleus Thus, a quantity of energy known as the ionization energy is required to remove one of the outermost electrons When an electron is removed from a neutral atom, a positive particle called a cation with a 1+ charge is formed Na1g2 + energy 1ionization2 h Na+ 1g2 + e- 4.7  Trends in Periodic Properties  The ionization energy decreases going down a group Less energy is needed to remove an electron because nuclear attraction decreases when electrons are farther from the nucleus Going across a period from left to right, the ionization energy increases As the positive charge of the nucleus increases, more energy is needed to remove an electron In Period 1, the valence electrons are close to the nucleus and strongly held H and He have high ionization energies because a large amount of energy is required to remove an electron The ionization energy for He is the highest of any element because He has a full, stable, energy level which is disrupted by removing an electron The high ionization energies of the noble gases indicate that their electron arrangements are especially stable In general, the ionization energy is low for the metals and high for the nonmetals 1see Figure 4.142 Ionization Energy Increases Ionization Energy Decreases Groups 1A 112 2A 122 Li Be B C N O F Ne Na Mg Al Si P S Cl Ar H 3A 4A 5A 6A 7A 8A 1132 1142 1152 1162 1172 1182 He K Ca Ga Ge As Se Br Kr Rb Sr In Sn Sb Te I Xe Cs Ba Tl Pb Po At Bi Rn Sample Problem 4.14 Ionization Energy Indicate the element in each group that has the higher ionization energy and explain your choice a K or Na b Mg or Cl c F, N, or C Solution a Na In Na, an electron is removed from an energy level closer to the nucleus, which requires a higher ionization energy for Na compared to K b Cl The increased nuclear charge of Cl increases the attraction for the valence electrons, which requires a higher ionization energy for Cl compared to Mg c F The increased nuclear charge of F increases the attraction for the valence electrons, which requires a higher ionization energy for F compared to C or N Study Check 4.14 Arrange Sn, Sr, and I in order of increasing ionization energy Metallic Character An element that has metallic character is an element that loses valence electrons easily Metallic character is more prevalent in the elements 1metals2 on the left side of the periodic table and decreases going from left to right across a period The elements 1nonmetals2 on the right side of the periodic table not easily lose electrons, which means they are the least metallic Most of the metalloids between the metals and nonmetals tend to lose electrons, but not as easily as the metals Thus, in Period 3, sodium, which loses electrons most easily, would be the most metallic Going across from left to right in Period 3, metallic character decreases to argon, which has the least metallic character 123 Figure 4.14  N  Ionization energies for the representative elements decrease going down a group and increase going across a period Q Why is the ionization energy for F greater than that for Cl? Chapter 4  Atoms and Elements Figure 4.15  N  Metallic character of the representative elements increases going down a group and decreases going from left to right across a period Q Why is the metallic character greater for Rb than for Li? For elements in the same group of representative elements, metallic character increases going from top to bottom Atoms at the bottom of any group have more electron levels, which makes it easier to lose electrons Thus, the elements at the bottom of a group on the periodic table have lower ionization energy and are more metallic compared to the elements at the top 1see Figure 4.152 Metallic Character Decreases Groups Metallic Character Increases 124  1A 112 2A 122 Li Be B C N O F Ne Na Mg Al Si P S Cl Ar H 3A 4A 5A 6A 7A 8A 1132 1142 1152 1162 1172 1182 He K Ca Ga Ge As Se Br Kr Rb Sr In Sn Sb Te I Xe Cs Ba Tl Pb Po At Bi Rn Sample Problem 4.15  Metallic Character Identify the element that has more metallic character in each of the following: a Mg or Al b Mg or Ca Solution a Mg is more metallic than Al because metallic character decreases going from left to right across a period b Ca is more metallic than Mg because metallic character increases going down a group Study Check 4.15 Of the elements Na, K, and S, which has the most metallic character? A summary of the trends in periodic properties we have discussed is given in Table 4.12 Table 4.12  Summary of Trends in Periodic Properties of Representative Elements Periodic Property Top to Bottom within a Group Left to Right across a Period Valence Electrons Remains the same Increases Atomic Size Increases due to the increase in number of energy levels Decreases due to the increase of protons in the nucleus that pull electrons closer Ionization Energy Decreases because valence electrons are easier to remove when they are farther away from the nucleus Increases as the attraction of the protons for outer electrons requires more energy to remove an electron Metallic Character Increases because valence electrons are easier to remove when they are farther from the nucleus Decreases as the attraction of the protons makes it more difficult to remove an electron 4.7  Trends in Periodic Properties  125 Questions and Problems 4.7 Trends in Periodic Properties Learning Goal  Use the electron arrangement of elements to explain the trends in periodic properties 4.47 What is the group number and number of valence electrons for each of the following elements? a magnesium b iodine c oxygen d phosphorus e tin f boron 4.48 What is the group number and number of valence electrons for each of the following elements? a potassium b silicon c neon d aluminum e barium f bromine 4.49 Write the group number and draw the electron-dot symbol for each of the following elements: a sulfur b nitrogen c calcium d sodium e gallium 4.50 Write the group number and draw the electron-dot symbol for each of the following elements: a carbon b oxygen c argon d lithium e chlorine 4.51 Select the larger atom in each pair a Na or Cl b.  Na or Rb c.  Na or Mg d.  Rb or I 4.52 Select the larger atom in each pair a S or Cl b.  S or O c.  S or Se d.  S or Mg 4.53 Place the elements in each set in order of decreasing atomic size a Al, Si, Mg b.  Cl, I, Br c.  Sr, Sb, I d.  P, Si, Na 4.54 Place the elements in each set in order of decreasing atomic size a Cl, S, P b.  Ge, Si, C c.  Ba, Ca, Sr d.  S, O, Se 4.55 Select the element in each pair with the higher ionization energy a Br or I b.  Mg or Sr c.  Si or P d.  I or Xe 4.56 Select the element in each pair with the higher ionization energy a O or Ne b.  K or Br c.  Ca or Ba d.  Ne or N 4.57 Place the elements in each set in order of increasing ionization energy a F, Cl, Br b.  Na, Cl, Al c.  Na, K, Cs d.  As, Ca, Br 4.58 Place the elements in each set in order of increasing ionization energy a O, N, C b.  S, P, Cl c.  As, P, N d.  Al, Si, P 4.59 Fill in the following blanks using larger or smaller, more metallic or less metallic Na has a atomic size and is than P 4.60 Fill in the following blanks using larger or smaller, higher or atomic size and a ionization lower Mg has a energy than Cs 4.61 Place the following in order of decreasing metallic character: Br, Ge, Ca, Ga 4.62 Place the following in order of increasing metallic character: Mg, P, Al, Ar 4.63 Fill in each of the following blanks using higher or lower, more or less: ionization energy and metallic char Sr has a acter than Sb 4.64 Fill in each of the following blanks using higher or lower, more or less: N has a acter than As ionization energy and metallic char- 4.65 Complete each of the statements a–d using 1, 2, or 3: decreases     2.  increases     3.  remains the same Going down Group 6A 1162, a the ionization energy b the atomic size c the metallic character d the number of valence electrons 4.66 Complete each of the statements a–d using 1, 2, or 3: decreases   2.  increases   3.  remains the same Going from left to right across Period 4, a the ionization energy b the atomic size c the metallic character d the number of valence electrons 4.67 Which statements completed with a–e will be true and which will be false? An atom of N compared to an atom of Li has a larger 1greater2 a atomic size b ionization energy c number of protons d metallic character e number of valence electrons 4.68 Which statements completed with a–e will be true and which will be false? An atom of C compared to an atom of Sn has a larger 1greater2 a atomic size b ionization energy c number of protons d metallic character e number of valence electrons CONCEPT MAP ATOMS AND ELEMENTS Elements consist of are Metals Metalloids Nonmetals Atoms that have that have Chemical Symbols Subatomic Particles arranged in the Periodic Table by Groups Periods Protons Neutrons Electrons determine make up the in Atomic Number Nucleus Energy Levels that has a have Mass Number Valence Electrons that differs in that determine Isotopes Periodic Trends that give such as Atomic Mass Group Number Electron-Dot Symbol Atomic Size Ionization Energy Metallic Character Chapter Review 4.1  Elements and Symbols Learning Goal  Given the 4.2  The Periodic Table Learning Goal  Use the periodic name of an element, write its ­correct symbol; from the symbol, write the correct name • Elements are the primary substances of matter • Chemical symbols are one- or ­two-letter abbreviations of the names of the elements table to identify the group and the period of an element; identify the element as a metal, a nonmetal, or a metalloid • The periodic table is an arrangement of the elements by increasing atomic number B 14 Si 32 33 Ge As 51 52 Sb Te 84 85 Po At 117 — Key Terms  • A horizontal row is called a period A vertical column on the periodic table containing elements with similar properties is called a group • Elements in Group 1A 112 are called the alkali metals; Group 2A 122, the alkaline earth metals; Group 7A 1172, the halogens; and Group 8A 1182, the noble gases • On the periodic table, metals are located on the left of the heavy zigzag line, and nonmetals are to the right of the heavy zigzag line • Except for aluminum, elements located along the heavy zigzag line are called metalloids 4.3  The Atom Learning Goal  Describe the elec- Electrons 1-2 trical charge and location in an atom for a proton, a neutron, and an electron • An atom is the smallest particle that retains the characteristics of an element Nucleus 1+2 • Atoms are composed of three types of subatomic particles • Protons have a positive charge 1+2, electrons carry a negative charge 1- 2, and neutrons are electrically neutral • The protons and neutrons are found in the tiny, dense nucleus; electrons are located outside the nucleus 4.4  Atomic Number and Mass Number Learning Goal  Given the 4.6  Electron Energy Levels Learning Goal  Given the name or symbol of one of the first 20 elements in the periodic table, write the electron arrangement High-energy • Every electron has a light emitted specific amount of energy • In an atom, the electrons of similar energy are grouped in specific energy levels • The first level nearest the nucleus can hold electrons, the second level can hold electrons, and the third level will take up to 18 electrons • The electron arrangement is written by placing the number of electrons in that atom in order from the lowest energy levels and filling to higher levels 4.7  Trends in Periodic Properties Learning Goal  Use the electron arrangement of ele- Li Neutron atomic number and the mass Proton Lithium protons number of an atom, state the number of protons, neutrons, and electrons Electron • The atomic number gives the number of protons in all the atoms of the same element • In a neutral atom, the number of protons and electrons is equal • The mass number is the total number of protons and neutrons in an atom 4.5  Isotopes and Atomic Mass Learning Goal Determine 127 Atomic the number of protons, electrons, structure of Mg and neutrons in one or more of the isotopes of an element; calculate the atomic mass of an Isotopes element using the percent of Mg abundance and mass of its naturally occurring isotopes 24 25 26 • Atoms that have the same number 12 Mg 12 Mg 12 Mg of protons but different numbers of neutrons are called isotopes • The atomic mass of an element is the weighted average mass of all the isotopes in a naturally occurring sample of that element ments to explain the trends in periodic properties • The properties of elements are Li atom related to the valence electrons of the atoms • With only a few exceptions, each group of elements has the same arrangement of valence electrons Na atom differing only in the energy level Distance between • Valence electrons are reprethe nucleus and sented as dots around the symbol valence electron of the element • The size of an atom increases K atom going down a group and decreases going from left to right across a period • The energy required to remove a valence electron is the ionization energy, which decreases going down a group, and increases going from left to right across a period • The metallic character of an element increases going down a group and decreases going from left to right across a period Key Terms alkali metals  Elements of Group 1A 112 except hydrogen; these are soft, shiny metals with one valence electron alkaline earth metals  Group 2A 122 elements, which have two valence electrons atom  The smallest particle of an element that retains the characteristics of the element atomic mass  The weighted average mass of all the naturally occur- ring isotopes of an element atomic mass unit 1amu2   A small mass unit used to describe the mass of very small particles such as atoms and subatomic particles; amu is equal to one-twelfth the mass of a 126C atom 128  Chapter 4  Atoms and Elements atomic number  A number that is equal to the number of protons in metallic character  A measure of how easily an element loses a an atom atomic symbol  An abbreviation used to indicate the mass number valence electron metalloid  Elements with properties of both metals and nonmetals, and atomic number of an isotope chemical symbol  An abbreviation that represents the name of an element electron  A negatively charged subatomic particle having a very small mass that is usually ignored in calculations; its symbol is e- electron-dot symbol  The representation of an atom that shows valence electrons as dots around the symbol of the element energy level  A group of electrons with similar energy group  A vertical column in the periodic table that contains elements having similar physical and chemical properties group number  A number that appears at the top of each vertical column 1group2 in the periodic table and indicates the number of electrons in the outermost energy level halogens  Group 7A 1172 elements—fluorine, chlorine, bromine, iodine, and astatine—which have seven valence electrons ionization energy  The energy needed to remove the least tightly bound electron from the outermost energy level of an atom isotope  An atom that differs only in mass number from another atom of the same element Isotopes have the same atomic number 1number of protons2, but different numbers of neutrons mass number  The total number of protons and neutrons in the nucleus of an atom metal  An element that is shiny, malleable, ductile, and a good conductor of heat and electricity The metals are located to the left of the heavy zigzag line on the periodic table located along the heavy zigzag line on the periodic table neutron  A neutral subatomic particle having a mass of about amu and found in the nucleus of an atom; its symbol is n or n0 noble gas  An element in Group 8A 1182 of the periodic table, generally unreactive and seldom found in combination with other elements nonmetal  An element with little or no luster that is a poor conductor of heat and electricity The nonmetals are located to the right of the heavy zigzag line on the periodic table nucleus  The compact, very dense center of an atom, containing the protons and neutrons of the atom period  A horizontal row of elements in the periodic table periodic table  An arrangement of elements by increasing atomic number such that elements having similar chemical behavior are grouped in vertical columns proton  A positively charged subatomic particle having a mass of about amu and found in the nucleus of an atom; its symbol is p or p+ representative elements  Elements found in Groups 1A 112 through 8A 1182 excluding B groups 13–122 of the periodic table transition elements  Elements located between Groups 2A 122 and 3A 1132 on the periodic table valence electrons  Electrons in the outermost energy level of an atom Core Chemistry Skills The chapter section containing each Core Chemistry Skill is shown in parentheses at the end of each heading Counting Protons and Neutrons 14.42 • The atomic number of an element is equal to the number of protons in every atom of that element The atomic number is the whole number that appears above the symbol of each element on the ­periodic table Answer: Atomic Mass Number of Number of Element Number Number Protons Neutrons Number of Electrons Kr equal to  number   of protons   1362 36 Atomic number = number of protons in an atom • Because atoms are neutral, the number of electrons is equal to the number of protons Thus, the atomic number gives the number of electrons • The mass number is the total number of protons and neutrons in the nucleus of an atom Mass number = number of protons + number of neutrons • The number of neutrons is calculated from the mass number and atomic number Number of neutrons = mass number - number of protons Example: Calculate the number of protons, neutrons, and electrons in a krypton atom with a mass number of 80 80 equal to  atomic  number   1362 equal to mass   number   number of   protons   80 - 36   = 44 Writing Atomic Symbols for Isotopes 14.52 • Isotopes are atoms of the same element that have the same atomic number but different numbers of neutrons • An atomic symbol is written for a particular isotope, with its mass number 1protons and neutrons2 shown in the upper left corner and its atomic number 1protons2 shown in the lower left corner Mass number 24 Mg 12 Atomic number Symbol of element Understanding the Concepts  129 Example: Calculate the number of protons and neutrons in the cad- • The metallic character of an element increases going down a group and decreases going from left to right across a period Answer: Example: For Mg, P, and Cl, identify which has the mium isotope 112 48Cd Isotope 112 48Cd Atomic Number Mass Number Number of Protons Number of Neutrons number   1482 in   lower left  corner number   11122   in upper  left  corner equal to  atomic  number   1482 equal to mass  number - number   of protons   112 - 48 = 64 Writing Electron Arrangements 14.62 • The electron arrangement for an atom specifies the energy levels occupied by the electrons of an atom • An electron arrangement is written starting with the lowest energy level, followed by the next lowest energy level Example: Write the electron arrangement for phosphorus Answer: Phosphorus has atomic number 15, which means it has 15 protons and 15 electrons 2,8,5 Identifying Trends in Periodic Properties 14.72 • The size of an atom increases going down a group and decreases going from left to right across a period • The ionization energy decreases going down a group and increases going from left to right across a period a largest atomic size b highest ionization energy c most metallic character Answer: a.  Mg  b.  Cl  c.  Mg Drawing Electron-Dot Symbols 14.72 • The valence electrons are the electrons in the outermost energy level • The number of valence electrons is the same as the group number for the representative elements • An electron-dot symbol represents the number of valence electrons shown as dots placed around the symbol for the element Example: Give the group number and number of valence elec- trons, and draw the electron-dot symbol for each of the ­following: a.  Rb  b.  Se  c.  Xe Answer: a.  Group 1A 112, one valence electron, Rb # b.  Group 6A 1162, six valence electrons, Se c.  Group 8A 1182, eight valence electrons, Xe Understanding the Concepts The chapter sections to review are shown in parentheses at the end of the question 4.69 According to Dalton’s atomic theory, which of the following are true or false? If false, correct the statement to make it true 4.32 a Atoms of an element are identical to atoms of other elements b Every element is made of atoms c Atoms of different elements combine to form compounds d In a chemical reaction, some atoms disappear and new ­atoms appear 4.70 Use Rutherford’s gold-foil experiment to answer each of the following: 14.32 a What did Rutherford expect to happen when he aimed particles at the gold foil? b How did the results differ from what he expected? c How did he use the results to propose a model of the atom? 4.71 Match the subatomic particles 11–32 to each of the descriptions below: 14.42 protons neutrons electrons a atomic mass b atomic number c positive charge d negative charge e mass number – atomic number 4.72 Match the subatomic particles 11–32 to each of the descriptions below: 14.42 protons neutrons electrons a mass number b surround the nucleus c in the nucleus d charge of e equal to number of electrons 4.73 Consider the following atoms in which X represents the chemical symbol of the element: 14.4, 4.52 16 8X 16 9X 18 10X 17 8X 18 8X a What atoms have the same number of protons? b Which atoms are isotopes? Of what element? c Which atoms have the same mass number? d What atoms have the same number of neutrons? 4.74 For each of the following, write the symbol and name for X and the number of protons and neutrons Which are isotopes of each other? 14.4, 4.52 a 124 b 116 c 116 47X 49X 50X 124 116 d 50X e 48X 4.75 Indicate if the atoms in each pair have the same number of protons, neutrons, or electrons 14.4, 4.52 38 34 39 a 37 b 36 c 40 17Cl, 18Ar 16S, 16S 18Ar, 17Cl 130  Chapter 4  Atoms and Elements 4.76 Complete the following table for the three naturally occurring isotopes of silicon, the major component in computer chips: 4.4, 4.52 4.78 Identify the element represented by each nucleus A through E in problem 4.77 as a metal, a nonmetal, or a metalloid 14.32 4.79 Match the spheres A through D with atoms of Li, Na, K, and Rb 14.72 A B C D 4.80 Match the spheres A through D with atoms of K, Ge, Ca, and Kr 14.72  omputer chips consist primarily of the C element silicon A Isotope 28 14Si 29 14Si 30 14Si Atomic Number Mass Number Number of Protons Number of Neutrons Number of Electrons 4.77 For each representation of a nucleus A through E, write the atomic symbol, and identify which are isotopes 14.4, 4.52 Proton Neutron A B C D E B C D 4.81 Of the elements Na, Mg, Si, S, Cl, and Ar, identify one that fits each of the following: 14.2, 4.6, 4.72 a largest atomic size b a halogen c electron arrangement 2,8,4 d highest ionization energy e in Group 6A 1162 f most metallic character g two valence electrons 4.82 Of the elements Sn, Xe, Te, Sr, I, and Rb, identify one that fits each of the following: 14.2, 4.6, 4.72 a smallest atomic size b an alkaline earth metal c a metalloid d lowest ionization energy e in Group 4A 1142 f least metallic character g seven valence electrons Additional Questions and Problems 4.83 Give the group and period numbers for each of the ­following elements: 14.22 a.  bromine  b.  argon  c.  potassium  d.  radium 4.84 Give the group and period numbers for each of the ­following elements: 14.22 a radon    b.  arsenic  c.  carbon      d.  neon 4.85 Indicate if each of the following statements is true or false: 14.32 a The proton is a negatively charged particle b The neutron is 2000 times as heavy as a proton c The atomic mass unit is based on a carbon atom with six protons and six neutrons d The nucleus is the largest part of the atom e The electrons are located outside the nucleus 4.86 Indicate if each of the following statements is true or false: 14.32 a The neutron is electrically neutral b Most of the mass of an atom is due to the protons and neutrons c The charge of an electron is equal, but opposite, to the charge of a neutron d The proton and the electron have about the same mass e The mass number is the number of protons 4.87 Complete the following statements: 14.2, 4.32 a The atomic number gives the number of _ in the nucleus b In an atom, the number of electrons is equal to the number of _ c Sodium and potassium are examples of elements called _ 4.88 Complete the following statements: 14.2, 4.32 a The number of protons and neutrons in an atom is also the _ number b The elements in Group 7A 1172 are called the _ c Elements that are shiny and conduct heat are called _ 4.89 Write the name and symbol of the element with the following atomic number: 14.1, 4.22 a 28 b 56 c 88 d 33 e 50 f 55 g 79 h 80 4.90 Write the name and symbol of the element with the following atomic number: 14.1, 4.22 a 36 b 22 c 48 d 26 e 54 f 78 g 83 h 92 Challenge Questions  4.91 For the following atoms, determine the number of protons, neutrons, and electrons: 14.4, 4.52 a.  114 b.  98 c.  199 43Tc 48Cd 79Au 136 222 d.  86Rn e.  54Xe 4.92 For the following atoms, determine the number of protons, neutrons, and electrons: 14.4, 4.52 a.  202 b.  127 c.  75 53I 35Br 80Hg 133 195 d.  55Cs e.  78Pt 4.93 Complete the following table: 14.4, 4.52 Name Atomic Symbol Number of Protons Number of Neutrons Number of Electrons 34 16S 28 14 220 86Rn 4.94 Complete the following table: 14.4, 4.52 Name Atomic Symbol Number of Protons Potassium Number of Neutrons Number of Electrons 22 51 23V 48 Barium 4.97 The most prevalent isotope of lead is 208 82Pb 14.4, 4.52 a How many protons, neutrons, and electrons are in 208 82Pb? b What is the atomic symbol of another isotope of lead with 132 neutrons? c What is the atomic symbol and name of an atom with the same mass number as in part b and 131 neutrons? 4.98 The most prevalent isotope of silver is 107 47Ag 14.4, 4.52 a How many protons, neutrons, and electrons are in 107 47Ag? b What is the atomic symbol of another isotope of silver with 62 neutrons? c What is the atomic symbol and name of an atom with the same mass number as in part b and 61 neutrons? 4.99 Write the group number and the electron arrangement for each of the following: 14.62 a oxygen b sodium c neon d boron 34 Magnesium 131 64 82 4.95 Write the atomic symbol for each of the following: 14.4, 4.52 a an atom with four protons and five neutrons b an atom with 12 protons and 14 neutrons c a calcium atom with a mass number of 46 d an atom with 30 electrons and 40 neutrons 4.96 Write the atomic symbol for each of the following: 14.4, 4.52 a an aluminum atom with 14 neutrons b an atom with atomic number 26 and 32 neutrons c a strontium atom with 50 neutrons d an atom with a mass number of 72 and atomic number 33 4.100 Write the group number and the electron arrangement for each of the following: 14.62 a magnesium b chlorine c beryllium d argon 4.101 Why is the ionization energy of Ca higher than K, but lower than that of Mg? 14.72 4.102 Why is the ionization energy of Cl lower than F, but higher than that of S? 14.72 4.103 Of the elements Li, Be, N, and F, which 14.72 a is an alkaline earth metal? b has the largest atomic size? c has the highest ionization energy? d is found in Group 5A 1152? e has the most metallic character? 4.104 Of the elements F, Br, Cl, and I, which 14.72 a has the largest atomic size? b has the smallest atomic size? c has the lowest ionization energy? d requires the most energy to remove an electron? e is found in Period 4? Challenge Questions The following groups of questions are related to the topics in this chapter However, they not all follow the chapter order, and they require you to combine concepts and skills from several sections These questions will help you increase your critical thinking skills and prepare for your next exam 4.105 There are four naturally occurring isotopes of strontium: 84 38Sr, 86 87 88 38Sr, 38Sr, 38Sr 14.4, 4.52 a How many protons, neutrons, and electrons are in Sr-87? b.  What is the most prevalent isotope in a strontium sample? c.  How many neutrons are in Sr-84? d.  Why don’t any of the isotopes of strontium have the atomic mass of 87.62 amu listed on the periodic table? 56 4.106 There are four naturally occurring isotopes of iron: 54 26Fe, 26Fe, 57 58 26Fe, and 26Fe 14.4, 4.52 a How many protons, neutrons, and electrons are in 58 26Fe? b What is the most prevalent isotope in an iron sample? c How many neutrons are in 57 26Fe? d Why don’t any of the isotopes of iron have the atomic mass of 55.85 amu listed on the periodic table? 4.107 Give the symbol of the element that has the 14.72 a smallest atomic size in Group 6A 1162 b smallest atomic size in Period c highest ionization energy in Group 5A 1152 d lowest ionization energy in Period e most metallic character in Group 2A 122 4.108 Give the symbol of the element that has the 14.72 a largest atomic size in Group 1A 112 b largest atomic size in Period c highest ionization energy in Group 2A 122 d lowest ionization energy in Group 7A 1172 e least metallic character in Group 4A 1142 4.109 A lead atom has a mass of 3.4 * 10-22 g How many lead atoms are in a cube of lead that has a volume of 2.00 cm3 if the density of lead is 11.3 g>cm3? 14.12 4.110 If the diameter of a sodium atom is 3.14 * 10-8 cm, how many sodium atoms would fit along a line exactly inch long? 14.12 132  Chapter 4  Atoms and Elements 4.111 Silicon has three naturally occurring isotopes: Si-28 127.977 amu2 with an abundance of 92.23%, Si-29 128.976 amu2 with a 4.68% abundance, and Si-30 129.974 amu2 with a 3.09% abundance Calculate the atomic mass for silicon using the weighted average mass method 14.52 4.112 Antimony 1Sb2 has two naturally occurring isotopes: Sb-121 and Sb-123 If Sb-121 has a 57.21% abundance and a mass of 120.9 amu, and Sb-123 has a 42.79% abundance and a mass of 122.9 amu, calculate the atomic mass for antimony using the weighted average mass method 14.52 Answers 4.21 In the process of brushing hair, strands of hair become charged with like charges that repel each other Answers to Study Checks 4.1 Si, S, and Ag 4.2 magnesium, aluminum, and fluorine 4.3 a Strontium is in Group 2A 122 b Strontium is an alkaline earth metal c Strontium is in Period 4.4 a arsenic, As b radon, Rn c boron, B 4.5 False; the nucleus occupies a very small volume in an atom 4.6 a 79 b 79 c gold, Au b 42 20Ca c 27 13Al 4.7 45 neutrons 4.8 a 157N 4.9 10.81 amu 4.23 a atomic number c mass number b both d atomic number 4.25 a lithium, Li c calcium, Ca e neon, Ne g iodine, I b fluorine, F d zinc, Zn f silicon, Si h oxygen, O 4.27 a 18 protons and 18 electrons b 25 protons and 25 electrons c 53 protons and 53 electrons d 48 protons and 48 electrons 4.29 Name of the Element 4.10 phosphorus 4.11 Group 5A 1152 Number Number Number Atomic Mass of of of Symbol Number Number Protons Neutrons Electrons 4.12 P 4.13 Ca Aluminum Al 13 27 13 14 13 Magnesium Mg 12 24 12 12 12 4.14 Ionization energy increases going left to right across a period: Sr is lowest, Sn is higher, and I is the highest of this set Potassium K 19 39 19 20 19 Sulfur S 16 31 16 15 16 Iron Fe 26 56 26 30 26 4.15 K Answers to Selected Questions and Problems 4.1 a Cu e Fe b Pt f Ba c.  Ca g.  Pb d.  Mn h.  Sr 4.3 a carbon   b.  chlorine    c.  iodine    d.  mercury e.  silver   f.  argon      g.  boron     h.  nickel 4.5 a sodium, chlorine b calcium, sulfur, oxygen c carbon, hydrogen, chlorine, nitrogen, oxygen d barium, chromium, oxygen b Group 8A 1182 d Period 4.7 a Period c Group 1A 112 4.9 a  needed for bone and teeth, muscle contraction, nerve impulses; alkaline earth metal b component of hemoglobin; transition element c muscle contraction, nerve impulses; alkali metal d found in fluids outside cells; halogen 4.11 a C d.  Ca b.  He e.  Al c.  Na 4.31 a 38 protons, 51 neutrons, 38 electrons b 24 protons, 28 neutrons, 24 electrons c 16 protons, 18 neutrons, 16 electrons d 35 protons, 46 neutrons, 35 electrons 4.33 a.  31 15P d.  35 17Cl b.  80 35Br e.  202 80Hg c.  122 50Sn 38 40 4.35 a 36 18Ar  18Ar  18Ar b They all have the same number of protons and electrons c They have different numbers of neutrons, which gives them different mass numbers d The atomic mass of Ar listed on the periodic table is the weighted average atomic mass of all the naturally occurring isotopes e The isotope Ar-40 is most prevalent because its mass is closest to the atomic mass of Ar on the periodic table 4.37 69.72 amu 4.39 absorb 4.41 a green light b.  blue light 4.13 a.  metal     b.  nonmetal      c.  metal     d.  nonmetal e.  nonmetal   f   nonmetal  g.  metalloid h.  metal 4.43 a 2,4 d 2,8,4 b 2,8,8 e c 2,8,8,1 f 2,5 4.15 a electron c electron 4.45 a Li d Cl b Mg e O c H b proton d neutron 4.17 Rutherford determined that an atom contains a small, compact nucleus that is positively charged 4.19 a True c True b True d False; a proton is attracted to an electron 4.47 a Group 2A 122, eb Group 7A 1172, ec Group 6A 1162, ed Group 5A 1152, ee Group 4A 1142, ef Group 3A 1132, e- Answers  4.49 a Group 6A 1162 4.83 a Group 7A 1172, Period b Group 8A 1182, Period c Group 1A 112, Period d Group 2A 122, Period S b Group 5A 1152 N c Group 2A 122 Ca d Group 1A 112 Na e Group 3A 1132 4.85 a False d False b False e True c True 4.87 a protons b.  protons c.  alkali metals 4.89 a nickel, Ni d arsenic, As g gold, Au b.  barium, Ba e.  tin, Sn h.  mercury, Hg c.  radium, Ra f.  cesium, Cs 4.51 a Na c Na b Rb d Rb 4.91 a 48 protons, 66 neutrons, 48 electrons b 43 protons, 55 neutrons, 43 electrons c 79 protons, 120 neutrons, 79 electrons d 86 protons, 136 neutrons, 86 electrons e 54 protons, 82 neutrons, 54 electrons 4.53 a Mg, Al, Si b.  I, Br, Cl 4.93   Ga c Sr, Sb, I d.  Na, Si, P 4.55 a Br c P b.  Mg d.  Xe Name 4.57 a Br, Cl, F c Cs, K, Na b.  Na, Al, Cl d.  Ca, As, Br Sulfur 34 16S 16  18 16 Nickel 62 28Ni 28  34 28 4.59 larger, more metallic Magnesium 26 12Mg 12  14 12 4.61 Ca, Ga, Ge, Br Radon 220 86Rn 86 134 86 4.63 lower, more 4.65 a decreases c increases b increases d remains the same 4.67 b, c, and e are true, a and d are false 4.69 a False; All atoms of a given element are different from atoms of other elements b True c True d False; In a chemical reaction atoms are never created or destroyed 4.71 a + d.  b.  e.  c.  4.73 a 168X, 178X, 188X all have eight protons b 168X, 178X, 188X are all isotopes of oxygen 18 c 168X and 169X have mass numbers of 16, and 18 10X and 8X have mass numbers of 18 d 168X and 18 10X have eight neutrons each 4.75 a Both have 20 neutrons b Both have 16 protons and 16 electrons c Both have 22 neutrons 4.77 a 94Be d.  105B b.  115B e.  c.  136C 12 6C Representations B and D are isotopes of boron; C and E are isotopes of carbon 4.79 Li is D, Na is A, K is C, and Rb is B 4.81 a Na e S b Cl f Na c Si g Mg d Ar 133 4.95 a 94Be Atomic Symbol Number of Number of Protons Neutrons b 26 12Mg c Number of Electrons 46 20Ca d 70 30Zn 4.97 a 82 protons, 126 neutrons, 82 electrons b 214 82Pb c 214 83Bi, bismuth 4.99 a O; Group 6A 1162; 2,6 b Na; Group 1A 112; 2,8,1 c Ne; Group 8A 1182; 2,8 d B; Group 3A 1132; 2,3 4.101 Calcium has a greater number of protons than K The increase in positive charge increases the attraction for electrons, which means that more energy is required to remove the valence electrons The valence electrons are farther from the nucleus in Ca than in Mg and less energy is needed to remove them 4.103 a Be d N b Li e Li c F 4.105 a 38 protons, 49 neutrons, 38 electrons b 88 38Sr c 46 neutrons d The atomic mass on the periodic table is the weighted average of all the naturally occurring isotopes 4.107 a O d Na 4.109 6.6 * 1022 atoms of Pb 4.111 28.09 amu b Ar e Ra c N ... Timberlake In addition to Chemistry: An Introduction to General, Organic, and Biological Chemistry, twelfth edition, she is also the author of General, Organic, and Biological Chemistry, Structures... 12842 12882 12932 12942 Chemistry An Introduction to General, Organic, and Biological Chemistry Twelfth Edition Karen C Timberlake Boston Columbus Indianapolis New York San Francisco Upper Saddle... alcohols and ethers and aldehydes and ketones has been deleted • A new table Solubility of Selected Aldehydes and Ketones has been added • A new Chemistry Link to Health, “Hand Sanitizers and Ethanol,”