7 New VocabularyChemical bondIonic bondCationAnion
8 Chemical Bond The force that holds two atoms together Three types Ionic bonds *Chap 7Metallic bonds *Chap 7Covalent bonds *Chap 8
9 Valence Electrons and Chemical Bonds Each valence electron is represented as a dot around the nuclear core of the element.
10 Valence Electrons and Chemical Bonds The most stable electron configuration for an element is the nearest noble gas.ns2np6OctetIons gain or lose electrons to achieve noble gas configurations
11 Octet RuleIn forming compounds, atoms tend to achieve the electron configuration of a noble gasns2np6Atoms of metals tend to lose their valence electrons leaving a complete octet in the next lowest energy levelAtoms of non-metals tend to gain electrons or to share electrons with another non metal to achieve a complete octet
13 Positive Ion Formation Cation: a positively charged ionResults when electrons are lost
14 Metal ions Group 1 loses 1 electron Group 2 loses 2 electrons +1 chargeGroup 2 loses 2 electrons+2 chargeGroup 13 loses 3 electrons+3 chargeGroups 3-12 usually lose 2 electronsMost have +2 charge (range from +1 to +3)
15 Negative Ion Formation Anion: negatively charged ionFormed when electrons are gainedNon-metals
17 Section SummaryA chemical bond is the force that holds two atoms togetherSome atoms gain or lose electrons to gain a stable configuration; these are called ionsMost stable configurations end: ns2np6.
18 Sodium Electron loss or ionization of sodium atom Na 1s22s22p63s1 → Na+ 1s22s22p6
19 The electron configuration of a sodium ion is the same as a neon atom
20 ChlorineA gain of one electron gives chlorine an octet and converts a chlorine atom into a chloride ion.It has the same electron configuration as argon20
22 Section 7.1 practice #1:1. How many valence electrons does each of the following atoms have?galliumfluorineselenium
23 Section 7.1 practice #2:2. For each element below, state (i) the number of valence electrons in the atom, (ii) the electron dot structure, and (iii) the chemical symbol(s) for the most stable ion.BaIK
24 Section 7.1 practice #33. Write the electron configuration for each of the following atoms and ions.K atomK ionc. Na atomd. Na ione. Phosphorous atomf. Phosphide ion
25 Section 7.1 practice #44. How many electrons will each element gain or lose in forming an ion? State whether the resulting ion is a cation or an anion.a. strontium (Sr)b. tellurium (Te)c. Bromine (Br)d. aluminum (Al)e. rubidium (Rb)f. Phosphorus (P)
27 7.2 Main IdeaOppositely charged ions attract each other forming electrically neutral ionic compounds.
28 7.2 ObjectivesDescribe the formation of ionic bonds and the structure of ionic compoundsGeneralize about the strength of ionic bonds based on the physical properties of ionic bondsCategorize ionic bond formation as exothermic or endothermic
38 Properties of Ionic Compounds Crystalline shape depends on the ions involved
39 Properties of Ionic Compounds Physical propertiesVery strongSolid at normal temperaturesVery high melting point and boiling pointMany have brilliant colors due to transition metalsHard, rigidBrittle
40 Properties of Ionic Compounds Conductivity (ability for electric charge to move through a substanceSolids have electrons locked in placeNon conductiveAqueous solutions have easily moveable electronsElectrolytesGood conductors
41 Properties of Ionic Compounds Dissolve in waterMay have radically different properties than the elements that compose themPolar Dissolution
43 Properties of Ionic Compounds Formation of lattice is always exothermic.
44 Section SummaryIonic compounds contain ionic bonds formed by the attraction of oppositely charged ions.Ions in an ionic compound are arranged in a repeating pattern called a lattice.Ionic compounds are electrolytes; they conduct electricity in liquid and aqueous states.
45 Can you…Describe the formation of ionic bonds and the structure of ionic compoundsGeneralize about the strength of ionic bonds based on the physical properties of ionic bondsCategorize ionic bond formation as exothermic or endothermic
68 Reduce to simplest form Mg2O2Both subscripts can be divided by 2 so the final formula isMgO
69 Why did we specify some oxidation numbers, but not others? PracticeSilver I and chlorineAntimony (V) oxideAluminum sulfideMagnesium and fluorineIron II and oxygenCalcium and phosphorusWhy did we specify some oxidation numbers, but not others?
70 Rules for Naming Binary Ionic Compounds State the name of the cation.(If using a transition metal, you must state the oxidation number if there is more than one possibility.)State the name of the anion, but change the ending to “ide.”
72 Tricky practiceFe2O3Iron is a transition metal so we need to figure out the charge before we can name the compound.We know oxygen is always -2, so there is an overall charge of -6 from the oxygenThat means Iron must supply an overall charge of +6This indicates that iron must have an oxidation number of +3 in this case
73 Tricky practiceFe2O3Iron III oxideCuSAgCl* (trick!)H2O
74 Monatomic Ions vs polyatomic Ions Monatomic ion: a one atom ionEx. Mg 2+Polyatomic ion: ions made up of more than atomEx. PO4 3-
75 OxyanionsOxyanions- a polyatomic ion composed of an element, usually a nonmetal, bonded to one or more oxygen atoms.The ion with the greater number of oxygen atoms ends in –ate.The ion with the fewer number of oxygen atoms ends in –ite.Ex. NO NO2-Nitrate Nitrite
76 Take out a sheet of paper Directions:Draw 5 by 5 chart.Write 5 metals ions in the left marginWrite 5 nonmetal ions on the topTrade charts with the person next to youFill in the charts by writing the correct formulas for the ionic compounds formed in the square.Hand the chart back to your partner when your done and check each others responses.Once finished, raise your hand and ask Mrs. Chebib to come over and stamp your work for credit
77 Naming Polyatomic Ions State the name of the cation.(If using a transition metal, you must state the oxidation number if there is more than one possibility.)Name the anion
78 Practice AgNO3 CaCO3 NH4Cl FeSO4 Silver nitrate Calcium carbonate Ammonium chlorideFeSO4Iron II sulfate
79 Writing formulas for ionic compounds with polyatomic ions Write out each ion.Place oxidation number under each ionCross multiplyReduce to simplest form
80 Side note Oxyanions are any polyatomic anions that contain oxygen Your book likes to sound fancy!
81 Writing formulas for ionic compounds with polyatomic ions You may not, under any conditions, change the subscripts within the polyatomic ion when balancing the charge. You may only adjust the number of units of each polyatomic ion!!Use parentheses to remind yourself that the units go together and cannot be changed.
82 Write out each ion.Potassium permanganateK (MnO4)
83 Place oxidation number under each ion Potassium permanganateK (MnO4)
95 Section SummaryA formula unit gives the ration of cations to anions in the ionic compound.A monatomic ion is formed from one atom.Roman numerals indicate the oxidation numbers of any element with more than one oxidation number.
96 Section SummaryPolyatomic ions consist of more than one atom and act as a single unit.To indicate more than one polyatomic ion in a chemical formula, place parentheses around the polyatomic ion and use a subscript outside the parentheses.
97 Can you… Relate a formula unit of an ionic compound to its composition Write formulas for ionic compounds and oxyanions.Apply naming conventions to ionic compounds and oxyanions.
98 7.4 Metallic Bonds and the Properties of Metals
99 7.4 Main IdeaMetals form crystal lattices and can be modeled as cations surrounded by a “sea” of freely moving valence electrons.
100 7.4 Describe a metallic bond Relate the electron sea model the physical properties of metalsDefine alloys and categorize them into two basic types.
107 Properties of Metals Melting and Boiling points Vary greatly Most are moderately high melting points and very high boiling points
108 Properties of Metals Malleability, ductility and durability Nuclei move relatively free of each other due to the sea of electrons
109 Properties of Metals Thermal and electrical conductivity Delocalized electrons quickly move heat from one part of the metal to other partsDelocalized electrons can move in one direction and create a “current.”
110 Properties of Metals Hardness and strength The number of delocalized electrons plays a role in the hardness of the metalMore delocalized electrons means a harder metalSometimes d level electrons are delocalized as well as the s resulting in very hard metals.
111 Metal Alloys Alloy- a mixture of elements that has metallic properties Characteristics may differ from the “parent” metalsInclude brass, bronze, 14-carat gold, stainless steel, etc.
112 Types of Metal Alloys Substitutional Some of the atoms from one metal are replaced by atoms of the other metalEx: brass
113 Types of Metal Alloys Interstitial Small holes in the lattice are filled by atoms of another elementExample: Steel
114 Section SummaryA metallic bond forms when metal cations attract freely moving, delocalized valence electrons.The electron sea model explains the physical properties of metallic solids.Metal alloys are formed when a metal is mixed with one or more other elements.
115 Can you… Describe a metallic bond Relate the electron sea model the physical properties of metalsDefine alloys and categorize them into two basic types.