1. II. Molecular Compounds

2. Covalent Bonding A major type of atomic bonding occurs when atoms share electrons.atoms As opposed to ionic bonding in which a complete transfer of electrons occurs,electrons

3. Covalent bonds Non metal + Non metal Example -Hydrogen + Hydrogen

4. Share electrons

5. A Shorthand Method for Drawing Covalent Bonds Straight lines can be used to represent a covalent bond between two atoms. Each line represents a shared pair of e -

6. Single bonds

7. O=C=O Carbon dioxide, CO 2 Double Bond

8. 1.Draw a skeleton structure. a.Determine the central atom 1. Largest atom or C Rules for drawing Lewis structures 2. Count total valence electrons on all atoms a. If the molecule is charged, add an electron for each negative charge and subtract an electron for each positive charge 3. Connect the structure. a. Draw a bond between the central atom and each outside atom. Each bond uses 2 valence electrons. 4. Make outside atoms happy fill valence energy levels 5.Place all remaining electrons on the central atom. a. the octet on the central atom is not complete, try sharing lone pairs of outside atoms to form double or triple bonds

9. Lewis structures Draw a covalent bond for –H 2 0 –H 2 0 2 –CH 4 –CO 2 –CO

10. Ch. 11 - Chemical Bonds III. Naming Molecular Compounds  Molecular Names  Molecular Formulas

11.  Write the names of both elements.  Change the final ending to -ide.  Add prefixes to indicate subscripts.  Only use mono- prefix with oxide. A. Molecular Names

12. PREFIX mono- di- tri- tetra- penta- hexa- SUBSCRIPT 1 2 3 4 5 6 A. Molecular Names

13.  CCl 4  N 2 O  SF 6 carbon tetrachloride dinitrogen monoxide sulfur hexafluoride A. Molecular Names

14.  Write the larger non metal first.  Add subscripts according to prefixes. B. Molecular Formulas

15.  phosphorus trichloride  dinitrogen pentoxide  dihydrogen monoxide PCl 3 N 2 O 5 H 2 O B. Molecular Formulas

16.  The Seven Diatomic Elements Br 2 I 2 N 2 Cl 2 H 2 O 2 F 2 B. Molecular Formulas

17. Covalent Bonding - True Molecules RETURN B. Types of Bonds Diatomic Molecule

18. C. Bond Polarity Most bonds are a blend of ionic and covalent characteristics. Difference in electronegativity determines bond type.

19. C. Bond Polarity Electronegativity –Attraction an atom has for a shared pair of electrons. –higher e - neg atom   - –lower e - neg atom   +

20. C. Bond Polarity Electronegativity Trend (p. 151) –Increases up and to the right.

21. Nonpolar Covalent Bond –e - are shared equally –symmetrical e - density –usually identical atoms C. Bond Polarity

22. ++ -- Polar Covalent Bond –e - are shared unequally –asymmetrical e - density –results in partial charges (dipole)

23. zNonpolar zPolar zIonic View Bonding Animations.Bonding Animations C. Bond Polarity

24. Examples: Cl 2 HCl NaCl 3.0-3.0=0.0 Nonpolar 3.0-2.1=0.9 Polar 3.0-0.9=2.1 Ionic