C. Lewis Dot Diagrams zElectron Dot Diagrams – model for showing ionic and covalent bonds yshow valence e - as dots ydistribute dots like arrows in an orbital diagram X

Gilbert Newton Lewis Invented “Electron-dot” formulas or “Lewis Structures” I’m so tired of writing all those useless inner electrons, in the Bohring models!

C. Lewis Structures zOctet Rule yMost atoms form bonds in order to obtain 8 valence e - yFull energy level stability ~ Noble Gases Ne

C. Lewis Structures zIonic – Show the transfer of e-

++ -- ++ C. Covalent – Electrons shared zNonpolar Covalent - no charges zPolar Covalent - partial charges

IIIIIIIV II. Naming Compounds Ch. 5 & 6 - Chemical Bonding

A. Vocabulary CHEMICAL BONDS 2 nonmetals Metal + Nonmetal IONICCOVALENT CO 2 NaCl e- transferred e- shared

A. Vocabulary CHEMICAL FORMULA Molecular Formula Unit IONICCOVALENT CO 2 NaCl

A. Vocabulary COMPOUND Ternary Compound Binary Compound 2 elements more than 2 elements NaNO 3 NaCl

A. Vocabulary ION Polyatomic Ion Monatomic Ion 1 atom 2 or more atoms NO 3 - Na + Cation Anion

B. Covalent/Molecular Nomenclature zPrefix System (binary compounds) 1.Less e - neg atom comes first. Ex. CO 2 2.Add prefixes to indicate # of atoms. Omit mono- prefix on first element. Ex.Carbon Dioxide 3.Change the ending of the second element to -ide.

PREFIX mono- di- tri- tetra- penta- hexa- hepta- octa- nona- deca- NUMBER B. Molecular Nomenclature

zCCl 4 zH 2 O zSF 6 ycarbon tetrachloride ydihydrogen monoxide ysulfur hexafluoride B. Molecular Nomenclature

zarsenic trichloride zdinitrogen pentoxide ztetraphosphorus decoxide yAsCl 3 yN2O5yN2O5 yP 4 O 10 B. Molecular Nomenclature

C. Ionic Nomenclature Ionic Formulas zWrite each ion, cation (+) first. Don’t show charges in the final formula. zOverall charge must equal zero. yIf charges cancel, just write symbols. yIf not, use subscripts to balance charges. Sodium Iodide: Na + I - NaI Calcium Bromide: Ca +2 Br - CaBr 2

NA C. Ionic Nomenclature

Ionic Names zWrite the names of both ions, cation (+) first. zChange ending of monatomic ions to -ide. zPolyatomic ions have special names. Use parentheses to show more than one polyatomic ion in a formula. zStock System - Use Roman numerals to show the ion’s charge if more than one is possible for the transition metals.

C. Ionic Nomenclature zConsider the following: yDoes it contain a polyatomic ion? x-ide, 2 elements  no x-ate, -ite, 3+ elements  yes yDoes it contain a Roman numeral? xCheck the table for metals not in Groups 1 or 2. yNo prefixes!

zpotassium chloride zmagnesium nitrate zcopper(II) chloride  K + Cl   Mg 2+ NO 3   Cu 2+ Cl   KCl  Mg(NO 3 ) 2  CuCl 2 C. Ionic Nomenclature

zMgBr 2 zNa 2 CO 3 zFeCl 3 ymagnesium bromide ysodium carbonate yiron(III) chloride C. Ionic Nomenclature

D. Hydrates yHydrates - Ionic compounds that absorb water into their solid structure yWater can be removed by heating yAnhydrous is the opposite and means “without water”.

D. Hydrates zFormula and name of a hydrate: CuSO 4 o 5H 2 0 Copper (II) Sulfate PentaHydrate CoCl 2 o 6H 2 0 Cobalt (II) Chloride HexaHydrate

E. Determining Charge yFind the charge of each ion and the total number of atoms: xNa 3 PO 4 : Chg: Na +1 PO 4 -3 –Na – 3 atoms; P – 1; O – 4 atoms xFe(OH) 3 : Chg: Fe +3 OH -1 –Fe – 1 atom; O – 3; H – 3 atoms xCu(NO 3 ) 2 : Chg: Cu +2 NO 3 -1 –Cu – 1 atom; N – 2; O – 6 atoms