1. IIIIIIIV Ch. 8 - Covalent Bonding I. The Covalent Bond (p. 240 – 247)

2. A. Why Do Atoms Bond? zGain stability zLower potential energy zAtoms that fulfill the octet rule are more stable balanced attraction & repulsion increased repulsion attraction vs. repulsion

3. B. What is a covalent bond? zA chemical bond that results from the sharing of electrons zMolecule = two or more atoms that are held together by covalent bonds zMajority of covalent bonds form between nonmetals (CLOSE together on periodic table) H2OH2O

4. Examples: zWhich of the following are covalent compounds? yNaBr ySiO 2 yCO 2 yAlCl 3 yCH 4

5. IONIC COVALENT Bond Formation Type of Structure Solubility in Water Electrical Conductivity Other Properties e - are transferred from metal to nonmetal high yes (solution or liquid) yes e - are shared between two nonmetals low no usually not Melting Point crystal lattice true molecules Properties Table Physical State solid liquid or gas odorous Form electrolytes in solution

6. C. Covalent Bonding Formation zDiatomic molecule = molecule containing only two atoms zSome atoms exist this way because they are more stable than the individual atoms Cl 2

7. NOF Cl Br I H D. Diatomic Elements zThe Seven Diatomic Elements Br 2 I 2 N 2 Cl 2 H 2 O 2 F 2

8. E. Lewis Structures zElectron Dot Diagrams yshow valence e - as dots ydistribute dots like arrows in an orbital diagram y4 sides = 1 s-orbital, 3 p-orbitals yEX: oxygen 2s2p O X

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

10. E. Lewis Structures zExample Electron Dot Notations: yCa yPyP yHyH yCyC Ca P

11. E. Lewis Structures zSingle Bonds yWhen atoms share one pair of electrons yThe two shared electrons belong to both atoms simultaneously yLewis Structure dots or a line symbolize a single covalent bond (1 pair of shared e-) H – H

12. zHow would you draw the Lewis structure for fluorine? zDiatomic! zF – F E. Lewis Structures

13. zMultiple Covalent Bonds yWhen atoms share more than one pair of electrons yHave higher bond energies and are shorter than single bonds

14. E. Lewis Structures zDouble Bonds ySharing two pairs of electrons between two atoms yDraw Lewis Structures for 2 oxygen atoms

15. E. Lewis Structures zTriple Bonds ySharing three pairs of electrons between two atoms yDraw Lewis Structures for 2 nitrogen atoms

16. IIIIIIIV Naming Molecules Section 8.2

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

18. PREFIX mono- di- tri- tetra- penta- hexa- hepta- octa- nona- deca- NUMBER 1 2 3 4 5 6 7 8 9 10 C. Molecular Nomenclature

19. zCCl 4 zN 2 O zSF 6 ycarbon tetrachloride ydinitrogen monoxide ysulfur hexafluoride C. Molecular Nomenclature

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

21. + - + B. Lewis Structures zNonpolar Covalent - no charges zPolar Covalent - partial charges