Chemistry 103EXAM I SurveyOutlineBondsIonic and Covalent BondsMetal Ions – Why Are They Positive?Nonmetal Ions – Why Are They Negative?Elements in a CompoundSalt is An Ionic CompoundIONIC COMPOUNDS - Lewis Dot Diagrams/Chemical FormulasNomenclature - Naming CompoundsNOMENCLATUREMonovalent Positive Ions (ions with only one charge)Periodic Table and Some IonsNaming Ionic CompoundsAnion StemsExamplesSlide 18Learning CheckSlide 20Polyatomic IonsPolyatomic Ions to MemorizeWhat if the Cation or the Anion is a Polyatomic Ion?Slide 24Molecules and Covalent CompoundsMoleculesMolecular CompoundsLewis Structures/Electron Dot DiagramsDiatomic ElementsCovalent Bonds & Lewis StructuresForming a H2 MoleculeH2, A Covalent Molecule (Elemental Form)Single Covalent BondsLewis Structures continued….Double BondsLewis Structure continued….Chemistry 103Lecture 10EXAM I SurveyHow did you do on this exam? (Grade range, don’t give your actual score)Did your performance meet your expectations?Did you complete and check the practice exam?Did you finish all homework?If you did not meet your performance expectations, what will you do differently next time?Please list any recommendations for improving the course.OutlineI. Ionic Compounds (in review)NomenclaturePolyatomic Ions/NomenclatureII. Covalent CompoundsLewis Dot Diagrams/Lewis structuresNomenclatureProperties predicted EXAM I SURVEYBondsIonic Bonds - electron transfer process. Typically between a metal and a nonmetalsCovalent Bonds - electrons shared. Typically involving nonmetals.Ionic and Covalent BondsAtoms acquire octets•To become more stable •By losing, gaining, or sharing valence electrons•By forming ionic bonds or covalent bonds Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin CummingsMetal Ions – Why Are They Positive?Let’s look at Mg. Its electron configuration is 1s22s22p63s2.If it loses two electrons to become Mg2+, it will have the electron configuration 1s22s22p6 8 Valence Electrons!If it gains 6 electrons to become Mg6-, it will have the electron configuration 1s22s22p63s23p68 Valence Electrons!The question is which is easier? To lose TWO electrons or to gain SIX?Losing two: Therefore, Mg tends to form Mg2+ ionsNonmetal Ions – Why Are They Negative?Let’s look at Cl. Its electron configuration is 1s22s22p63s23p5.If it loses seven electrons to become Cl7+, it will have the electron configuration 1s22s22p6 8 Valence Electrons!If it gains 1 electron to become Cl-, it will have the electron configuration 1s22s22p63s23p68 Valence Electrons!The question is which is easier? To lose SEVEN electrons or to gain ONE?Gaining ONE: Therefore, Cl tends to form Cl- ionsElements in a Compound“Table salt” is a compound that contains the elements sodium and chlorine.Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings9Salt is An Ionic CompoundSodium chloride in “table salt” is an example of an ionic compound. Chemical Formula: NaClCopyright © 2005 by Pearson Education, Inc.Publishing as Benjamin CummingsIONIC COMPOUNDS - Lewis Dot Diagrams/Chemical FormulasCa and BrLi and ONomenclature - Naming CompoundsFIRST QUESTION: IONIC or COVALENT????IONIC NOMENCLATURE RULES (Metal + Nonmetal)NOMENCLATURE ( Metal + Nonmetal )IONIC COMPOUNDS Metal Metal (fixed charge) (variable charge)?Monovalent Positive Ions (ions with only one charge)Periodic Table and Some Ions Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin CummingsNaming Ionic CompoundsFirst word of name:Name of metal in fullIf the metal can have more than one positive charge, the charge is indicated in parentheses in the name. Examples: Cu+ = copper (I); Cu2+ = copper (II).Second word of name:Name of anion (second element in formula) with “-ide” endingAnion StemsExamplesK3NAuCl3 PbSChromium (III) oxideIron (II) oxideMagnesium ChloridePeriodic Table and Some Ions Copyright © 2005 by Pearson Education, Inc.Publishing as Benjamin Cummings19Learning CheckThe correct formula for each of the following is:1. Copper (I) nitride A) CuN B) CuN3 C) Cu3N2. Lead (IV) oxide A) PbO2B) PbO C) Pb2O420Learning CheckThe correct formula for each of the following is:1. Copper (I) nitride A) CuN B) CuN3 C) Cu3N2. Lead (IV) oxide A) PbO2B) PbO C) Pb2O4Polyatomic IonsPolyatomic ionAn ion formed from a group of atoms (held together by covalent bonds) through loss or gain of electronsCan be the positive or the negative ion in an ionic compound22NO3- nitrateNO2- nitriteOH-hydroxideSO42-sulfateSO32-sulfiteCO32-carbonate PO43- phosphate NH4+ammoniumPolyatomic Ions to MemorizeWhat if the Cation or the Anion is a Polyatomic Ion?Name of polyatomic ion replaces the first word of the name (if the polyatomic ion is positive) or the second word of the name (if the polyatomic ion is negative)NH4ClK2SO4Co2(CO3) 3Ammonium nitrateWhat if the Cation or the Anion is a Polyatomic Ion?Name of polyatomic ion replaces the first word of the name (if the polyatomic ion is positive) or the second word of the name (if the polyatomic ion is negative)NH4Cl Ammonium ChlorideK2SO4Potassium SulfateCo2(CO3) 3Cobalt(III) CarbonateAmmonium nitrate NH4NO3Molecules and Covalent CompoundsMoleculesMolecules are made up of two or more atoms, either of the same element or of two or more different elements, joined by one or more covalent chemical bonds (shared electrons).Molecular CompoundsMolecular Compounds are made up of two or more atoms of two or more different elements, joined by one or more covalent chemical bonds (shared electrons).Lewis Structures/Electron Dot DiagramsLewis structures show us how atoms are bonded to each other. They can be used to predict molecular shapes, bond strength and bond length.29Diatomic Elements•These elements share electrons to form diatomic, covalent molecules.Covalent Bonds & Lewis StructuresFormed when two (or more) nonmetals share valence electrons in order to obey the octet rule.Single bond: two atoms share a pair of electrons between them (2 shared electrons = 1 bond)Example: H2Forming a H2 MoleculeCopyright © 2008 by Pearson Education, Inc.Publishing as Benjamin CummingsH2, A Covalent Molecule (Elemental Form)In a hydrogen (H2) molecule •Two hydrogen atoms share electrons to form a