2Chemical Bonds There are three basic types of bonds: Ionic - The electrostatic attraction between ionsCovalent - The sharing of electrons between atomsMetallic - Each metal atom bonds to other metals atoms within a "sea" of electrons (covered in a later unit)
3Periodic Table - Review The periodic table is "periodic" because of certain trends that are seen in the elements.Properties of elements are functions of their atomic number.Elements from the same family/group have similar physical and chemical properties.Atoms are listed on the periodic table in rows, based on number of protons, which is equal to the number of electrons in a neutral atom.
4The Periodic Table of the Elements The periodic table can be also divided into metals (left/blue) and nonmetals (right/yellow).A few elements retain some of the properties of metals and nonmetals, they are called metalloids (staircase/pink).AsBSiTeGeSb?
5In the periodic table, the elements are arranged in __________. 1In the periodic table, the elements are arranged in __________.Aalphabetical orderBorder of increasing atomic numberCorder of increasing metallic propertiesDorder of increasing neutron contentEreverse alphabetical orderFI don't know how to answer this.
62Elements __________ exhibit similar physical and chemical properties.Awith similar chemical symbolsBwith similar atomic massesCin the same period of the periodic tableDon opposite sides of the periodic tableEin the same group of the periodic tableFI don't know how to answer this.
73Which pair of elements would you expect to exhibit the greatest similarity in their physical and chemical properties?AH, LiBCs, BaCCa, SiDGa, GeEC, OFI don't know how to answer this.
8Which one of the following is a nonmetal? 4Which one of the following is a nonmetal?AWBSrCOsDIrESFI don't know how to answer this.
95 Potassium is a __________ and chlorine is a __________. E F B D A C metal, nonmetalBmetal, metalCmetal, metalloidDmetalloid, nonmetalEnonmetal, metalFI don't know how to answer this.
10Review: Octet RuleAtoms tend towards having complete outer shells of electrons (remember stability).A full outer shell will have: 2 electrons in the s subshell and 6 electrons in the p subshell ( s2p6 configuration)Octet rule: atoms tend towards having a total of 8 electrons8 valence electrons make an octet
11Valence ElectronsValence electrons are the electrons in the highest occupied energy level of an element’s atoms.The number of valence electrons largely determines the chemical properties of an element.ValenceelectronTo find the number of valence electrons in an atom of a representative element, simply look at its group number.Atoms in group 3 have 3 valence electrons,atoms in group 17 have 7 valence electrons, etc.
12Valence Electrons Number of valence electrons in neutral atoms: 1 - 4There is one exception:helium has only 2 valence electrons.
13C 3 7 27 5 B D E A 6 How many valence electrons does Aluminum have? I don't know how to answer this.
14D 3 E 52 C A 1 B 2 7 How many valence electrons does Barium have? I don't know how to answer this.
15IonsCations are positive and are formed by elements on the left side of the periodic chart (metals).Anions are negative and are formed by elements on the right side of the periodic chart (nonmetals).
16The Formation of Cations Metals usually give up valence electronsThis results in a noble gas (8 electron) outer shell.Na : 1s2 2s2 2p6 3s Na+1 : 1s2 2s2 2p6Loss of valence electronsNe atomThe configuration of the Sodium ion is the same as Neon
17The Formation of Cations Na atomNa+ ionloses e-11p11e-10e-
18(+2 indicates 2 units of positive charge) The Formation of CationsCations of Group 1A elements always have a charge of 1+.Cations of Group 2A elements always have a charge of 2+.MgMg2+2e-+Magnesium atom(electricallyneutral,charge = 0)Magnesium ion(+2 indicates 2 units of positive charge)(2 in front of e- indicates 2 units of negative charge)
19The Formation of Anions Nonmetals usually gain valence electrons.This results in a noble gas (8 electrons) outer shellCl: 1s2 2s2 2p6 3s2 3p5Cl- 1s2, 2s2, 2p6, 3s2, 3p6Ar atomA chloride ion has the same electron configuration as argon.
20The Formation of Anions Cl atomCl- ionGains an e-17P17e-17p18e-
21The Formation of Anions Anions of Group 15 (5A) elements have a charge of 3-Anions of Group 16 (6A) elements always have a charge of 2-Anions of Group 17 (7A) elements have a charge of 1-
228Metals tend to __________ electrons and cations tend to __________ electrons.Again, gainBlose, loseCgain, loseDlose, gainEneither, they keep their electronsFI don't know how to answer this.
239 Anions tend to be __________ and cations tend to be __________. A E metals, metalsBnonmetals, nonmetalsCmetals, nonmetalsDnonmetals, metalsEmetalloids, metalloidsFI don't know how to answer this.
2410Metals lose electrons to form cationsTrueFalse
2612Nonmetals tend to lose electrons forming ionsTrueFalse
2713This is the ion formed from a calcium atomACa+BCa2+CCa-DCa2-EI don't know how to answer this.
2814Barium forms an ion with a charge of __________.A1+B2-C3+D3-E2+FI don't know how to answer this.
29Aluminum forms an ion with a charge of __________. 15Aluminum forms an ion with a charge of __________.A2+B1-C3+D2-EFI don't know how to answer this.
3016Of the following, __________ contains the greatest number of electrons.AP3+BPCP2-DP3-EP2+FI don't know how to answer this.
31D E 3+ F 17 3- Oxygen forms an ion with a charge of __________. A 2- C B2+C3-D3+E6+FI don't know how to answer this.
3218 B E 1- F Iodine forms an ion with a charge of __________. A 7- 1+ 2-D2+E1-FI don't know how to answer this.
33C D E A N3- B N2- N3+ 19 I don't know how to answer this. This is the ion formed from nitrogenAN-BN2-CN3+DN3-EI don't know how to answer this.
3420 Predict the charge of the most stable ion of S? E F 2- 3+B1-C6+D2+E2-FI don't know how to answer this.
35Ionic BondingElectronegativity is how strongly an atom attracts electrons.Atoms with a high electronegativity will be able to attract electrons away from atoms with a much lower electronegativity.This removal of electrons can occur when the difference in electronegativity between the two atoms is approximately 1.7 or higher.Once a positive and negative ion are formed, they will be attracted to each other via the electrostatic force:r2F = k q1 q2Note: The heavier nonmetals from 4,6,5th groups( In, Tl, Sn, Pb, Sb Bi )may act like metals
36Ionic BondingAn electronegativity difference of approximately 1.7 can only occur between a metal and a nonmetal.
3721 Which pair of atoms will form an ionic bond? D C E A B Li and Ne K and BrCK and CsDS and ClEI don't know how to answer this.
3822 Which pair of atoms will form an ionic bond? C A D E Li and Be B Na and MgCK and CaDNa and ClEI don't know how to answer this.
3923Which of the following compounds would you expect to be ionic?AH2OBCO2CSrCl2DSO2EH2SFI don't know how to answer this.
40Formation of Ionic Compounds Compounds composed of cations and anions are called ionic compounds.Although they are composed of ions, ionic compounds are electrically neutral.The electrostatic forces that hold ions together in ionic compounds are called ionic bonds.
41Ionic BondsWhen sodium and chlorine are close together, sodium's valence electron flies off and "harpoons" the chlorine atom.The result is a sodium cation (+) next to a chloride anion (-)These oppositely charged two ions attract: they reel one another together to form an ionic bond.1s2 2s2 2s2 2p6 3s1 1s2 2s2 2p6 3s2 3p s2 2s2 2p6 1s2 2s2 2p6 3s2 3p6NaClNa+Cl-1s2 2s2 2p6 1s2 2s2 2p6 3s2 3p6NeAr
42click here for an animation of this reaction Ionic BondsThe electron transfer process in creating an ionic bond:NaClThe dots represents the valence electrons in an atom.click here for an animation of this reaction
43Formula UnitsA chemical formula shows the kinds and numbers of atoms in the smallest representative unit of a substance.A formula unit is the lowest whole-number ratio of ions in an ionic compound.Every ionic compound has a 3D array of positive and negative ions.
44Properties of Ionic Compounds [*]Properties of Ionic CompoundsThey are crystalline solids at room temperatureThey have high melting pointsThey conduct electricity when melted (molten) or dissolved in water (aqueous)
45of potassium and oxygen? Predicting an Ionic Compound FormulaPredicting the formula of the ionic compoundPotassium (K) with an electronegativity of 0.8 and oxygen (O) with an electronegativity of 3.5 will form an ionic compound.What is the formula for an ionic compoundof potassium and oxygen?How many additional valence electrons does oxygen want? 2How many valence electrons does potassium have? 1How many potassium atoms will it take to give oxygen the electrons it needs? The formula unit is K2OKOAlways Metal First (low electonegativity)
46Mg Predicting an Ionic Compound Formula N Predicting the formula of the ionic compoundPredicting an Ionic Compound FormulaWhat is the formula for an ioniccompound of Mg and N?How many additional valence electrons does N want? 3How many valence electrons does Mg have to offer? 2How many Mg atoms will it take to give how many N the electrons it needs? (Find the lowest common multiplier first.)3 Mg : 2 NThe formula unit is Mg3N2MgN
47Alternate MethodIf you don't like finding least common multipliers, you can use this alternative method:1. Write down the ions side by side along with their charge. Always write the metal first.2. "Criss-cross" the numerical values of the charges.3. Reduce subscripts to lowest ratio.MgN
48Predicting an Ionic Compound Formula Example: Write the formula for calcium sulfide.Step 1: Identify the cation & write its common ion Calcium is in group 2 Ca2+Step 2: Identify the anion & write its formula Sulfur is in group 6 S2-Step 3: Criss-cross; reduce subscripts if necessaryCa S2-Ca2S2CaS
49Predicting an Ionic Compound Formula What is the compound formed between Mg and S?Always use the lowest ratio of the ions!MgSMg S-2Mg2S2
50B D E A C OCs2 OCs2 I don't know how to do this. CsO2 Cs2O 24 The formula for the ionic between Cs and O is:ACsO2BOCs2CCs2ODOCs2EI don't know how to do this.
51C D E A B Ca2N2 Ca3N2 Ca2N3 I don't know how to do this. CaN 25 The ionic compound between Ca and N is:ACaNBCa2N2CCa3N2DCa2N3EI don't know how to do this.
52B C D E A AlO Al2O2 Al2O3 Al3O2 26 The ionic compound between Al and O I don't know how to do this.
53C D E A B CaAl Ca3Al2 Al2Ca3 27 No compound is formed. What is the ionic compound formed between Ca and Al?ACaAlBCa3Al2CAl2Ca3DNo compound is formed.EI don't know how to do this.
54B D E A C P3Br BrP (BrP)2 no ionic compound 28What is the ionic compound formed between P and Br?AP3BrBBrPCno ionic compoundD(BrP)2EI don't know how to do this.
5529What is the formula for sodium phosphide?ASP3BNaPCNa3PDNaP3EI don't know how to do this.
56D E B C A BrSr2 SrBr2 Sr2Br SrBr 30 I don't know how to do this. What is the formula for strontium bromide?ASrBrBSrBr2CSr2BrDBrSr2EI don't know how to do this.
5731The formula for barium sulfide is Ba2S2.TrueFalse
58Naming Binary Ionic Compounds - Cations Many cations have the same name as the original, neutral atom.Charge formula name______________________________H Hydrogen ionLi Lithium ionK Potassium ionCs Cesium ionAg Silver ionMg Magnesium ionCa Calcium ionBa Barium ionZn Zinc ionCd Cadmium ionAl Aluminum ion
59Naming Binary Ionic Compounds - Anions All monoatomic anions all end in "-ide".The ions that are produced from Group 7A (or 17)elements are called halide ions.Group Group GroupNitride N3- Oxide O Fluoride F-Phosphide P3- Sulfide S Chloride Cl-Iodide I-Bromide Br-
60Naming Binary Ionic Compounds Binary (two-element) compounds are named by writing the name of the cation followed by the name of the anion.The name of the cation is the same as the metal name.The name of the anion is the name of the non-metal withthe suffix changed to -ide.Binary compounds end in "-ide."Examples:NaCl = sodium chlorideKI = potassium iodideLi2S = lithium sulfide
61E D A 32 Na2S is B C I don't know how to do this. Sodium sulfate Sodium sulfideCDi-sodium sulfideDSulfur nitrideEI don't know how to do this.
62D E C F 33 A The correct name for SrO is __________. strontium oxide B strontium hydroxideCstrontium peroxideDstrontium monoxideEstrontium dioxideFI don't know how to do this.
63D A B C E F 34 dialuminum oxide aluminum oxide The correct name for Al2O3 is __________.Aaluminum trioxideBdialuminum oxideCdialuminum trioxideDaluminum oxideEaluminum hydroxideFI don't know how to do this.
64Cations formed by Transition Elements Recall that s-block metals have only one possible ionic charge, based on the Octet Rule.However, most transition metals can have more than one ionic charge. For this reason, there is a system for designating each ion.Sn, Pb from the p block will form more than one type of ions and behave like transition metals.
65Cations Formed by Transition Elements Only common transition metals are shown.Silver, cadmium and zinc only form one cation, Ag+, Cd2+ and Zn2+Note the mercury cations.Tin and Lead act like transition metals.
66Cations formed by Transition Elements We will use the Stock naming system (Roman numerals) to name transition metals.Formula Name_____________________________Cu Copper (I) ionCo Cobalt (II) ionFe Iron (II) ionMn Manganese (II) ionPb lead (II) ionCr Chromium (III) ionFe Iron (III) ion
67Writing Formulas with Transition Metals The charge on the cation is indicated by the Roman numeral, as shown in this example.Iron (III) oxide Write ion formulas.Fe3+ O2-Fe3+ O2-Criss-cross charges. Fe2O3Reduce if necessary.
68Writing Formulas with Transition Metals The charge on the cation is indicated by the Roman numeral, as shown in this example.Tin (IV) oxide Write ion formulas.Criss-cross charges. Reduce if necessary. SnO2 Sn2O4 Sn4+ O2- Sn4+ O2-
6935Which metal is capable of forming more than one cation?AKBCsCBaDAlESnFI don't know how to answer this.
7036Which metal is not capable of forming more than one cation?ACuBAuCFeDSnEAlFI don't know how to answer this.
71D C A B iron (III) chloride 37 iron (II) chloride The name of FeCl3 is iron chlorideBiron (II) chlorideCiron (III) chlorideDI don't know how to answer this.
72 Total cation charge + Total anion charge = 0 Formulas with Transition MetalsIn order to correctly name a formula containing a transition metal, it is necessary to first determine the charge on the cation.Since all compounds are neutral, then the total positive cation charge must equal the total negative anion charge.In other words: Total cation charge + Total anion charge = 0(charge of cation) (# of cations) + (charge of anion) (# of anions) = 0
73Example Formula with Transition Metals In the case of FeCl3, we make the following substitutions:(charge of cation) (# of cations) +(charge of anion) (# of anions) = 0(x) (1) + (-1) (3) = 0Thus x = 3 and the cation is Fe3+ or iron(III).
74Formulas with Transition Metals A short cut method is to "uncriss-cross" the ions, but you must always double check your ions (or you'll get in trouble!).FeCl3: Fe1 Cl3 Fe3+ Cl1-Cl does form a 1-ionand Fe3+ is Iron (III) Iron (III) ClorideUncriss-cross.Check the ions
75(this formula had to be reduced from Cr2O2) Formulas with Transition Metals Cr1 O1 CrO: Uncriss-cross.O forms a 2- ionandCr+ does not exist!(this formula had to be reduced from Cr2O2) Cromium (II) OxideCr+ O-Check the ionsHere's another practice problem.
76E B A C D SnO 38 SnO Sn2O The formula for tin (IV) oxide is SnO2 [*]38The formula for tin (IV) oxide isASnOBSn2OCSnO2DSnOEI don't know how to answer this.
77E A B C Cu2 S2 D 39 CuS2 (CuS)2 The formula for copper (II) sulfide is I don't know how to answer this.
78F E D C Cu3Cl2 B A Cu2Cl2 Cu2Cl CuCl2 40 CuCl Which one of the following compounds is copper(I) chloride?ACuClBCuCl2CCu2ClDCu2Cl2ECu3Cl2FI don't know how to answer this.
7941The charge on the cation in the salt Fe2O3 is __________.A1+B2+C3+D5-E6-FI don't know how to answer this.
80E A B C D 2+ 2- 4+ 42 What is the charge on zirconium ion in ZrO2 ? 1+ [*]42What is the charge on zirconium ion in ZrO2 ?A2+B4+C1+D2-EI don't know how to answer this.
81Polyatomic IonsA polyatomic ion is a group of atoms bonded together that have a charge and acts like a single unit or ion.They are not free compounds and are not found free in nature.They are found combined with other ions.Eg: Sulfate = (SO4 )2-Nitrate = (NO3) -Carbonate = (CO3) 2-Notes: Use " ( ) " to keep the atoms together. Do not change the subscripts inside the "( )"
82Examples: sulfite /sulfate Polyatomic Ions (con't)Most of the polyatomic ions contain oxygen atoms.Many anions names end with “-ite” or “-ate”In “ite/ate” pairs, the ion with fewer oxygen atomswill have the “ite” endingExamples: sulfite /sulfate nitrite /nitrateNote that the suffix does not indicate the actual number of O atoms.
83Polyatomic Ions (cont.) Familiarize yourself with the polyatomic ions on your reference sheetBe careful of -ide, -ite, and -ate!H+ = protonor hydrogen ionor bicarbonate]
84 CaCO3 calcium carbonate (in eggshells) Naming Ternary Ionic CompoundsTernary ionic compounds contain three or more different elements due to the presence of polyatomic ion(s).Just as in binary ionic compounds, the name of the cation is given first, followed by the name of the anion.Names of ternary compounds often end in -ite or -ate.Examples CaCO3 calcium carbonate (in eggshells) Zn(C2H3O2)2 zinc acetate AgNO3 silver nitrate Na2SO3 sodium sulfite
85Ternary Ionic Compounds Writing Formulas forTernary Ionic CompoundsTernary ionic compounds are neutral, just like binary ionic compounds. Therefore, the goal is to find the lowest ratio of cations to anions that will yield a neutral compound. This ratio is represented in a formula unit.Examples of formula unitsCa(CO3 ) Zn(C2H3O2)2Ag(NO3) Na2(SO3)
86Ternary Ionic Compounds (con't) Writing Formulas forTernary Ionic Compounds (con't)To write a formula, the criss-cross method can again be used.Example: Write the formula for lithium phosphate.Step 1: Identify the cation & write its formula Lithium is in group 1 --> Li +Step 2: Identify the anion & write its formula Phosphate is a polyatomic ion --> PO43-Step 3: Criss-cross; reduce subscripts if necessaryLi1+PO43-Li3(PO4)1 or simply Li3(PO4)
87Ternary Ionic Compounds Writing Formulas forTernary Ionic CompoundsExample: Write the formula for calcium nitrite.Ca2+(NO3)-Ca(NO3)2When writing formulas with polyatomic ions, there are two important things to remember:1) It is helpful to use " ( ) " to keep the atoms together, keeping the charge OUTSIDE the ( ) For example: nitrate (NO3)1- carbonate (CO3) 2-2) NEVER alter any symbols or subscripts INSIDE inside the "( )"
88E D B A C 43 Na(HO) The formula for sodium hydroxide is Na(OH) Na(OH2) I don't know how to answer this.
89E A B C D 44 The formula for aluminum phosphate is: Al(PO4 ) Al3(PO4) I don't know how to answer this.
90E B A D C 45 Mg(CO3) The formula for magnesium carbonate is : Mg(CO3)2 I don't know how to answer this.
91E A C D 46 B Ca(SO3) The formula for calcium sulfate is Ca(SO4) I don't know how to answer this.
92E C sodium chlorite D B 47 NaClO is A sodium chloride sodium chlorateBsodium chlorideCsodium chloriteDsodium hypochloriteEI don't know how to answer this.
93E B 48 Mg(HCO3)2 is A C I don't know how to answer this. Magnesium carbonateBMagnesium hydrogen carbonateCMagnesium hydroxideDMagnesium carboxideEI don't know how to answer this.
94E A B C D 49 (NH4)(CO3) Ammonium carbonate is (NH4)2(CO3) (NH4)(CO3)2 I don't know how to answer this.
95Writing Formulas for Ionic Compounds PRACTICEWriting Formulas for Ionic CompoundsComplete the table by filling in the formula for the ionic compound formed by each pair of cations and anions, as shown for the first pair.
96Writing Formulas for Ionic Compounds PRACTICEWriting Formulas for Ionic CompoundsWrite the formula for the following compounds:1. Magnesium iodide2. Calcium sulfite3. Barium hydrogen carbonate4. Iron (III) phosphate