Chapter 2 Atoms, Molecules, And Ions - KFUPM
08-Sep-11Chapter 2Atoms, Molecules, and IonsDr. A. Al-Saadi1PreviewReviewing the fundamental chemical laws. UnderstandingU ddi theh moderndviewi off atomicistructure, molecules, and ions. Being familiar with main groups ofelements in the periodic table. Naming simple compounds,compounds ioniccompounds, and getting the chemicalformulas from the names. Dr. A. Al-Saadi21
08-Sep-11Chapter 2Section 1The Atomic TheoryIn 1808, John Dalton presented his theory.1. An element is made up from extremely small particlescalled atoms. Atoms of a given element are identical,but are different for different elements.Dalton had no idea what an atom would look like!2. Elements combine to form chemical compounds.3. A chemical reactioneaction involvesvo ves rearrangementea a ge e t ofo atoms;ato s; ittdoesn’t create or destroy them.Atoms » Elements » Molecules (Compounds)Dr. A. Al-Saadi3Chapter 2Section 1The Atomic TheoryCombination of oxygen and carbon to form carbon dioxideDr. A. Al-Saadi42
08-Sep-11Chapter 2Section 1Law of Definite Proportion By Joseph Proust.Different samples of a given compound alwayscontain the same elements in the same massratio.Dr. A. Al-Saadi5Chapter 2Section 1What Did Dalton Observe in CO Molecules?Mass ofoxygen thatcombines with1g of carbonRatio of mass ofoxygen thatcombines with 1gof carbon12or111.33g2.66gDr. A. Al-Saadi2etc.24oretc.1163
08-Sep-11Chapter 2Section 1Law of Multiple Proportions By John Dalton.If two elements can combine to form more thanone compound with each other, the masses ofone element that combine with a fixed mass ofthe other element are in ratios of small wholenumbers.Dr. A. Al-Saadi7Chapter 2Section 1Law of Multiple Proportions Dr. A. Al-SaadiFor several compounds of nitrogen (N) and oxygen (O),the followingg results were observed:Compound AMass of Nitrogen thatcombines with 1g ofOxygen1.750 gCompound B0 8750 g0.8750Compound C0.4375 g84
08-Sep-11Chapter 2Section 1Law of Multiple ProportionsMass of Nitrogen thatcombines with 1g ofOxygenMass of N in ACompound A1.750 gCompound B0.8750 gCompound C0.4375 g Mass of N in CMass of N in BMass of N in C4ABC1 21The mass ratios showncan be readily describedon basis of the ratios ofnumber of atoms.Dr. A. Al-Saadi9Chapter 2Section 1Law of Conservation of Mass Matter can be neither created nor destroyed.Because matter is made up of atoms that areunchanged (masses and properties) in a chemicalreaction, it follows that mass must be conservedas well.Combination of oxygen and carbon to form carbon dioxideDr. A. Al-Saadi105
08-Sep-11Chapter 2Section 2Early Imagination of the Atom What did Dalton think about the structure of anatom? Extremely small.Invisible.Has a mass.The smallest size ever of matter.No internal structure.By mid 1800’s it became evident that atoms aredivisible - there is an internal structure to theatom. (subatomic particles)Dr. A. Al-Saadi11Chapter 2Section 2Cathode Ray ExperimentDr. A. Al-Saadi126
08-Sep-11Chapter 2Section 2Cathode Ray Experiment The Deflection of the ray by a magnet indicates thatthe rayy is made upp of negativelygy chargedg pparticles.Thomson measured thecharge-to-mass ratio as:e 1.76 108 C/gmDr. A. Al-Saadi13Chapter 2Section 2Cathode Ray Experiment Dr. A. Al-SaadiCathode ray experiments revealedimportant conclusions about thestructure off theh atom. The ray is a stream of negativelycharged particles (later on calledelectrons). All atoms must containelectrons. Since the atom is neutral overall,overallit must have a positively chargedcomponent.Plum-pudding modelsuggested by Thomson147
08-Sep-11Chapter 2Section 2Mass of the Electron Mass of the electron:Millikan’s Experiment (1917).Oil ddropletsl tDr. A. Al-Saadi15Chapter 2Section 2RadioactivityTypes of spontaneous radioactive emission: α particles: have ve charge andhave mass that is7300 time themass of electronβ particles: highspeed electrons.γ particles: highenergy light.Dr. A. Al-Saadi168
08-Sep-11Chapter 2Section 2Rutherford ExperimentDr. A. Al-Saadi17Chapter 2Section 2The Proton and the Nucleus Dr. A. Al-SaadiRutherford Experiment (1910)189
08-Sep-11Chapter 2Section 2The Nuclear Atom Rutherford’s Model vs. Thomson’s Model.Thomson’s model(The plum-pudding model)Rutherford’s model(The nuclear atom)Dr. A. Al-Saadi19Chapter 2Section 2The Nuclear AtomMain components of atoms:Outside the nucleus: Electrons: are responsible forthe chemistry of the atom.Inside the nucleus: Protons: are positively chargedparticles whose charge is equali magnitudeinit d tot thatth t forfelectrons.The simplest viewof the atomDr. A. Al-Saadi2010
08-Sep-11Chapter 2Section 2The Nuclear Atom Nucleus is very tiny in terms ofsize.Each proton carries exactly theopposite charge of an electron.Almost all the atomic mass isconcentrated in it (very dense)!!The mass of the proton is1 67 10-24 g.1.67 10gIf a nucleus were to have thesize of a pea, it would weigh250,000,000,000 kg!10-8 cm 100 picometer1 10-121 picometer (pm) mDr. A. Al-Saadi21Chapter 2Section 2The Nuclear Atom Dr. A. Al-SaadiRutherford’s model left one problem: If H has a mass of 1, then He should have a massof 2. But its mass is 4!J. Chadwick (1932) discovered the neutrons;massive but uncharged particles.2211
08-Sep-11Chapter 2Section 3Atomic Number and Mass NumberMass number2311NaAtomic numberElement symbolElement symbol (Na) Sodium (Note that it is neutral)Mass number (A) # of protons # of neutronsAtomic number (Z) # of protonsFor Na ion, the charge # of protons – # of electronsDr. A. Al-Saadi23Chapter 2Section 3Atomic Symbols in the Periodic TableHydrogen (name)Sodium [original name is Natriam]Dr. A. Al-Saadi2412
08-Sep-11Chapter 2Section 3ExerciseAtomic number # of protons 63 EuAtomic mass # of protons # neutrons 63 88Atomic charge 63 – 60 3 3 The symbol is 15163 EuAnother exercise: For5326Fe 2 # of protons 26# of neutrons 53 – 26Net charge 2 # of electrons 26 – 2 24Dr. A. Al-Saadi25Chapter 2Section 3IsotopesIsotopes show almostidentical propertiesMass numberAZXAtomic numberIon(Cation)Sodium-232311Dr. A. Al-SaadiNaIsotopesSodium-241 # of protons 11# of neutrons 12# of electrons 102613
08-Sep-11Chapter 2Section 3Isotopes Isotopes of Hydrogen H dHydrogen((protium)i ) Deuterium TritiumThe chemical properties of an element aredetermined by the electrons and protons, not theneutrons. Thus, isotopes are chemically alike.Dr. A. Al-Saadi27Chapter 2Section 3How are Atomic Masses Measured?The Mass SpectrometerDr. A. Al-Saadi2814
08-Sep-11Chapter 2Section 3Mass Spectrum of XenonThree isotopes of neon existin nature with differentabundance.Dr. A. Al-Saadi29Chapter 3Section 3Mass Spectrum of Carbon1/10000 the sizeof large peakCarbon exists inthe form of threeisotopes: 12C (98.93%) 13C (1.07%) 14C ( 0.001%).Three isotopes of carbon are present in natureC-12 is the most abundant isotope of carbon.Dr. A. Al-Saadi3015
08-Sep-11Chapter 2Section 4The Periodic Table Scientists noticed that chemical and physicalpropertiesppof certain groupsg p of elements aresimilar to one another.This led to the development of the periodic table.Dr. A. Al-Saadi31Chapter 2Section 4The Modern Periodic TableTiDr. A. Al-Saadi3216
08-Sep-11Chapter 2Section 4The Modern Periodic Table- Periods : horizontalrows- Families (Groups) :vertical columnsElements in the samefamily have similarchemical and physicalpropertiesTi- Arranged in order ofincreasing atomicnumberDr. A. Al-Saadi33Chapter 2Section 4The Modern Periodic Table Metals: compose most of the periodic table. They have characteristicphysical properties e.g. High heat and electric conduction, malleability (hammered to sheet),ductility (pulled into wires). Tend to lose electrons to form ve ions. Fe2 , Fe3 , Na ,K , Ca2 .Nonmetals: lack the physical properties of metals. Tend to gain electrons to become –ve ions, like Cl-, F-, O2-, S2-. Tend to bond with each other by forming (covalent bonds), such asCl2, HCl,, N2O,, CO2 etc. react with metals to form salt (ionic bonds), such as NaCl, CaF2, etc.Metalloids: have intermediate properties. Dr. A. Al-SaadiExamples are B, Si, Ge, etc.3417
08-Sep-11Chapter 2Section 4The Modern Periodic Table- The metallic propertiesincrease as going fromright to left across aperiod.- The groups in theperiodic table are givenspecial names. Alkali metals.Ti Alkaline earth metalsmetals. Chalcogens Halogens. Nobel gasses. Transition metals.Dr. A. Al-Saadi35Chapter 2Section 4The Modern Periodic Table-TheThe groups in theperiodic table aregiven special names. Alkali metals. Alkaline earth metals. Chalcogens Halogens. Nobel gasses. Transition metals.Dr. A. Al-Saadi3618
08-Sep-11Chapter 2Section 5Atomic Masses Atomic mass is the mass of anatom expressed in atomic massunit (amu).By definition used by modernsystems, carbon-twelve 12C isassigned a mass of exactly 12amu.O atomicOnei mass uniti isi definedd fi das tha mass exactly equal to1/12 the mass of one carbon-12atom.Dr. A. Al-Saadi37Chapter 2Section 5Atomic Masses Carbon-12 (12 amu) provides the standard for measuringthe atomic mass of the rest of elements.Example: Hydrogen atom 1H was found to be 8.3985%as massive as the C-12 atom. Can you find the atomicmass of a hydrogen atom in amu?Mass 1H 12 amu 0.083985 1.0078 amu.Dr. A. Al-Saadi3819
08-Sep-11Chapter 2Section 5Average Atomic MassesWhy the carbon in theperiodic table has a masspmoff12.01 amu and not 12 amu?Carbon exists naturally as amixture of three isotopes, 12C,13C and 14C and thus the atomicmass unit used for the carbonatom ini theh periodici di tablebl isi thehaverage value of the masses ofthose isotopes.Dr. A. Al-Saadi39Chapter 2Section 5Average Atomic MassesThe average atomic mass (or justthe atomic mass) of the carbonatom 98.89% of 12 amu (12C) 1.11% of 13.0034 amu (13C) (0.9889)(12 amu) (0.0111)(13.0034 amu) 12.011 amu Dr. A. Al-SaadiThat is applied for all theelements of the periodic table.4020
08-Sep-11Chapter 2Section 5Average Atomic Masses Remember that, there is no asingle carbon atom that has themass of 12.010 amu. This is theaverage mass per carbon atomThat is applied for all theelements of the periodic table.The mass of each element listedin the periodic table is an averagevalue based on the isotopiccomposition of the naturallyoccurring element.Dr. A. Al-Saadi41Chapter 3Section 5ExerciseAtomic mass (mass of isotope 1 x fractional abundance of 1) (mass of isotope 2 x fractional abundance of 2) (mass of isotope 3 x fractional abundance of 3) .Dr. A. Al-Saadi4221
08-Sep-11Chapter 3Section 5ExerciseAtomic mass mi xii187Reis 62.60% with a mass of 186.956 amu.Mass of Re 186.207 amu (186.956amu) (0.6260) (? amu) (0.3740)Answer isMass of 185Re 184.9533 amu 185.0 amuDr. A. Al-Saadi43Chapter 2Section 6Molecular Compounds & Ionic Compounds Dr. A. Al-SaadiThe force holds atoms together is called achemical bond.bondSome types of chemical bonds are Covalent bonds: Two atoms “usuallynonmetals” can form a bond by sharingelectrons to produce “molecular compounds”. Ionic bonds: Two oppositely charged ions (acation and an anion) “a metal and a nonmetal”can form a bond by attraction to produce “ioniccompounds”.4422
08-Sep-11Chapter 2Section 6Molecular Compounds Molecule : combination of atleast two atoms in a specificarrangement held together bychemical bonds. May be an element or acompound.H2, hydrogen gas,gas is an element.elementH2O, water, is a compound.They are also called “binarycompounds”.N2COCH4Dr. A. Al-SaadiChapter 245Section 6Molecular Compounds Diatomic Molecule: Homonuclear (2 of the sameatoms) Examples: H2, N2, O2, F2,Cl2, Br2, and I2 Polyatomic Molecule: Dr. A. Al-SaadiContain more than 2 atomsMost moleculesMay contain more than oneelementExamples: ozone, O3; whitephosphorus, P4; water, H2O,and methane (CH4)Heteronuclear (2 differentatoms) Examples: CO and HCl4623
08-Sep-11Chapter 2Section 6Molecular Formulas Molecular formula: shows exact number ofatoms of each element in a molecule. Subscripts indicate number of atoms of eachelement present in the formula.Example: H2O, NH3, C12H22O11 etc.StructuralStt l formula:fl showshththe generallarrangement of atoms within the molecule.Dr. A. Al-Saadi47Chapter 2Section 6Molecular FormulasCovalent-bonded MoleculesDr. A. Al-Saadi4824
08-Sep-11Chapter 2Section 6Molecular Formulas Allotrope: one of two or more distinct formsof an element. oxygen, O2 and ozone, O3 (allotropic forms ofoxygen)diamond and graphite (allotropic forms of carbon)Dr. A. Al-Saadi49Chapter 2Section 6Naming Molecular Compounds Only usedfor thensecondelementDr. A. Al-SaadiIt is also known as“Nomenclature”Nomenclature .Binary molecular (or covalent)compounds are composed of twononmetals: Name the first element. Name the second elementchanging ending to “-ide”.ide . If the two elements form morethan one type of binarymolecular compounds then useprefixes to indicate number ofatoms of each element.5025
08-Sep-11Chapter 2Section 6Naming Molecular Compounds Only usedfor thensecondelement HClSiCNON2ON2O5SO2PCl3Hydrogen chlorideSilicon carbideNitrogen monoxideDinitrogen monoxideDinitrogen pentoxideSulfur dioxidePhosphorus trichlorideDr. A. Al-Saadi51Chapter 2Section 6Naming Molecular Compounds Name the following: Dr. A. Al-SaadiCl2ODichlorine monoxide.CBr4Carbon tetrabromide.ClO2Chlorine dioxide.SOSulfur monoxide.5226
08-Sep-11Chapter 2Section 6Naming Molecular Compounds The names of molecular compounds containinghydrogen do not usually follow the systematicnomenclature guidelines. B2H6 diborane SiH4silane NH3ammonia PH3phosphineh hi H2Owater H2Shydrogen sulfideDr. A. Al-Saadi53Chapter 2Section 6Naming Binary Acids Dr. A. Al-SaadiAcids when are dissolved in water, they produceH ions (protons) in the solutionssolutions. Examples are: HCl, HBr.Binary acids: Many have 2 names Pure substance: HCl, hydrogen chloride. Aqueous solution: when dissolved inwater it is called hydrochloric acid.5427
08-Sep-11Chapter 2Section 6Naming Binary Acids In order to name binary acids: Remove the “–gen”–gen ending from hydrogen leaving“hydro–”.Change the “–ide” ending on the second element to“–ic”.Combine the two words and add the word “acid”.Name the following: HBrHydrogen bromide ; Hydrobromic acidH2SHydrogen sulfide ; Hydrosulfuric acidDr. A. Al-Saadi55Chapter 2Section 6Naming Organic Compounds Organic Compounds: contain carbon andhydrogeny g (sometimes(with oxygen,yg , nitrogen,g ,sulfur and the halogens). Hydrocarbons : contain only carbon andhydrogen. Alkanes : simplest examples ofhydrocarbons. Their names depend on thenumber of carbon atoms in the molecule.molecule Inorganic Compounds: normally do notcontain carbon.Dr. A. Al-Saadi5628
08-Sep-11Chapter 2Section 6AlkanesDr. A. Al-Saadi57Chapter 2Section 6AlkanesDr. A. Al-Saadi5829
08-Sep-11Chapter 2Section 6Functional Groups Many derivatives ofalkanes are derived byreplacing a hydrogenwith one or morefunctional groups.Functional groupddeterminesichemicalh i lproperties and isresponsible forchemical reactions.Dr. A. Al-Saadi59Chapter 2Section 6Empirical Formulas Empirical Formula: tells: what elements are present in a molecule.molecule In what whole-number ratio they arecombined.Molecular(true)H 2O 2N 2H 4H 2ODr. A. Al-SaadiEmpirical(simplest)HOONH2H 2O6030
08-Sep-11Chapter 2Section 6Molecular and Empirical FormulasDr. A. Al-Saadi61Chapter 2Section 7Ionic Bonds and Ionic Compounds11 protons11 electronsNa17 protons17 electronsClNa -Cle-Na 11 protons10 electronsDr. A. Al-Saadi-Cl 17 protons18 electronsIn form of crystals,called ionic solidor commonlyknown as salt6231
08-Sep-11Chapter 2Section 7Ions and Ionic Compounds Ion: an atom or group of atomsthat has a net ppositive ornegative charge.Monatomic ion : one atom witha positive or negative charge.Cation : ion with a net positivecharge due to the loss of one ormore electrons.electronsAnion : ion with a net negativecharge due the gain of one ormore electrons.Dr. A. Al-SaadiNa -Cl63Chapter 2Section 7Common Monoatomic IonsCations: Lithium ion (Li ) Potassium ion ((K ) Aluminum ion (Al3 )Type IDr. A. Al-Saadi Iron (II) ion (Fe2 ) Iron (III) ion (Fe3 )( 4 ) Lead ((IV)) (Pb Lead (II) (Pb2 )Type II6432
08-Sep-11Chapter 2Section 7Common Monoatomic IonsAnions: Fluoride ion (F–) Oxide ion ((O2–) Nitride ion (N3–)Dr. A. Al-Saadi65Chapter 2Type ISection 7Naming Binary Ionic Compounds -It contains a ve ion and a –ve ion.1- Cations named firstthen anions.22- CationC ti elementlt hash thethsame name withoutchange.3-Use –ide root to theanion name.4-Double check the ionicchargesg to have thecorrect chemical formula.5-You will need topractice this table.Dr. A. Al-Saadi6- You will need to beable to get names fromformulas and vise versa.6633
08-Sep-11Chapter 2Type ISection 7Naming Binary Ionic CompoundsCompoundIonspresentNameNaClNa , Cl-SodiumchlorideKIK , I-PotassiumiodideCaSCa2 , S2-CalciumsulfideMgOMg2 , O2-MagnesiumoxideAl2O3Al3 , O2-AluminumoxideDr. A. Al-Saadi67Chapter 2Section 7Exercise Dr. A. Al-SaadiRb2ORubidium oxide.CaSCalcium sulfide.AlI3Aluminum iodide. Strontium fluoride.SrF2Aluminum selenide.Al2Se3Magnesium phosphide.Mg3P26834
08-Sep-11Chapter 2Type IISection 7Naming Binary Ionic Compounds Only for metals that can form morethan one typeyp off cations, the chargegmust be specified using RomannumeralsExamples: CuClCopper(I) chloride. CuClC Cl2Copper(II) chloride. CoCl3Cobalt(III) chloride.Dr. A. Al-Saadi69Chapter 2Section 7Polyatomic Ions Dr. A. Al-SaadiPolyatomic ions : ions that are a combination of two ormore atoms.7035
08-Sep-11Chapter 2Section 7Polyatomic IonsoxoanionsDr. A. Al-Saadi71Chapter 2Section 7ExerciseBaSO3Barium sulfite K2Cr2O7Potassium dichromate CuMnO4CCopper(I)(I) permanganatet NaNO2Sodium nitrite Dr. A. Al-SaadiChromium(III) hydroxideCr(OH)3 Magnesium cyanideMg(CN)2 Lead(IV) carbonatePb(CO3)2 Ammonium hypochloriteNH4ClO 7236
08-Sep-11Chapter 2Section 7Naming Binary CompoundsIonic compoundMolecular compoundDr. A. Al-Saadi73Chapter 2Section 7Naming Acids & Oxoacids Oxoacids : when ionized in water, they give H ions(protons)) and the corresponding(ppg polyatomicp yoxoanions inthe solutions.Examples: HNO3, H2SO3, and HC2H3O2.When writing formulas, add the number of H ionsnecessary to balance the corresponding oxoanion’snegative charge.charge- HXwhere X is an oxoanion HDr. A. Al-Saadi H2-X7437
08-Sep-11Chapter 2Section 7Naming Acids & Oxoacids HNO2. HNO3. H2SO3. H3PO4. Hydrochloricyacid (HCl).() Hydrobromic acid (HBr). Nitric acid. Phosphoric acid. Nitrous acid. Sulfurous acid.Dr. A. Al-Saadi75Chapter 2Section 7Naming Acids & OxoacidsDr. A. Al-SaadiAcidAnionNameHClOHypochloriteHypochlorous acidHClO2Chl itChloriteChlChlorousacididHClO3ChlorateChloric acidHClO4PerchloratePerchloric acid7638
08-Sep-11Chapter 2Section 7Hydrates Hydrates : compounds that have a specific number ofwater molecules within their solid structure Hydrated compounds may be heated to remove thewater forming an anhydrous compoundName the compound and add the word hydrate. Indicatethe number of water molecules with a prefix on hydrate. Example: CuSO4 · 5 H2O CopperC(II) sulfatelf t pentahydratet h d tDr. A. Al-Saadi77Chapter 2Section 7ExerciseLead(II) acetateCopper(II) sulfateCalcium oxideMagnesium sulfateMagnesium hydroxideCalcium sulfateDinitrogen monoxideDr. A. Al-Saadi7839
08-Sep-11 1 Chapter 2 Atoms, Molecules, and Ions Dr. A. Al-Saadi 1 Preview Reviewing the fundamental chemical laws. Ud di h d i f iUnderstanding the modern view of atomic structure, molecules, and ions. Being familiar with main groups of elements in the periodic table. Namingsimplecompoundsionic Dr. A. Al-Saadi 2 Naming simple compounds, ionic
A. 1.13 1024 atoms B. 1.48 1025 atoms C. 2.44 1022 atoms D. 3.22 1023 atoms E. 6.98 1021 atoms 50. How many atoms are in 7.12 mol of gold, Au? A. –1.18 10 23 atoms B. 244.29 10 atoms C. 8.46 1022 atoms D. 4.70 1024 atoms E. 3.34 1026 atoms 51. How many moles are
CARBON-BASED MOLECULES Reinforcement KEY CONCEPT Carbon-based molecules are the foundation of life. Carbon atoms are the basis of most molecules that make up living things. Many carbon-based molecules are large molecules called polymers that are made of many smaller, repeating molecules called monomers. There are four main types of
Part One: Heir of Ash Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 Chapter 24 Chapter 25 Chapter 26 Chapter 27 Chapter 28 Chapter 29 Chapter 30 .
Atoms, Molecules, and Ions The theory that atoms are the fundamental building blocks of matter reemerged in the early 19th century, championed by John Dalton. Dalton's Postulates Each element is composed of extremely small particles called atoms All atoms of a given element are identical to one another in mass and other
TO KILL A MOCKINGBIRD. Contents Dedication Epigraph Part One Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Part Two Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18. Chapter 19 Chapter 20 Chapter 21 Chapter 22 Chapter 23 Chapter 24 Chapter 25 Chapter 26
AJR Ch2 Atoms, Molecules and Ions.docx Slide 1 Chapter 2: Atoms, Molecules, and Ions (Ch2 Chang, Chs 0 and 2 Jespersen) Atoms are the basic building blocks of matter. They are the smallest particles of an element that retain the chemical identity of the element, or, the basic unit of an element that can enter into chemical combination.
a. nitrogen. c. water. b. carbon dioxide. d. oxygen. ANS: D DIF: 1 OBJ: 6-1.3 21. During the Calvin cycle, carbon-containing molecules are produced from a. carbon atoms from ATP. b. carbon atoms, hydrogen atoms, and oxygen atoms from glucose. c. carbon atoms from carbon dioxide in the air and hydrogen atoms from water.
atoms held together by chemical bonds. Example: Table salt, NaCl Also the smallest unit of a compound. Not all molecules are compounds. H2, O 2, and other diatomic gases are not molecules. Why? 3 How are molecules formed? The number of electrons in the outermost electron shell determine whether an atom is reactive or inert. Carbon .
