Chapter 8: Covalent Bonding Resources: Chapter 8 of our TB and unit 6 of workbook

1. Chapter 8: Covalent Bonding • Resources: • Chapter 8 of our TB and unit 6 of workbook • Ch. 8 reading and study guide (in part) • Powerpoint used in class • Lab practical: Molecular models • Handouts: practice problems and naming of covalent/molecular compounds • Animations and simulation • Simulations and animations: • Ionic and covalent bonding animation: http://www.youtube.com/watch?v=QqjcCvzWwww • Animation and song: what kinds of bonds are these: • http://www.youtube.com/watch?v=oNBzyM6TcK8 • Mark Rosengarten video tutorials on polarity of molecules: • http://www.youtube.com/watch?v=mtRgeBSe1o8&feature=related • glencoe animations and interactive lesson: • http://glencoe.mcgraw-hill.com/sites/0078807239/student_view0/chapter9/concepts_in_motion.html# • Animation: Ionic compounds versus nonpolar and polar molecules • Properties of ionic and covalent compounds:

2. 8.1 Molecules and Molecular Compounds • In nature, matter takes many forms. The noble gases, including helium and neon, are monatomic. That means they exist as single atoms. • Represented by symbols: He, Ne, etc) • the noble gases are not molecules

3. 8.1 Molecules and Molecular Compounds • A molecule is a neutral group of atoms joined together by covalent bonds. Air contains oxygen molecules. • A diatomic molecule is a molecule consisting of two atoms. An oxygen molecule is a diatomic molecule.

4. 8.1 Molecules and Molecular Compounds • Some elements do exist as diatomic molecules. • Hydrogen H2 (g) • Oxygen O2 (g) • Fluorine F2 (g) • Bromine Br2 (l) • Iodine I2 (s) • Nitrogen N2 (g) • Chlorine Cl2 (g)

5. 8.1 Molecules and Molecular Compounds • Pneumonic device to remember those elements that exist in nature as diatomic molecules.? (HOFBrINCl) • (write out symbols, add 2 as a subscript) H O F Br I N Cl H2 O2 F2 Br2 I2 N2 Cl2 • (note these are molecules but they are not compounds)

6. 8.1 Molecules and Molecular Compounds • A compound composed of molecules is called a molecular compound. Water and carbon monoxide are molecular compounds.

7. 8.1 Molecular Formulas • Formulas of Some Molecular Compounds

8. 8.1 Molecules and Molecular Compounds

9. 8.1 Molecular Formulas • A molecular formula is the chemical formula of a molecular compound. • A molecular formula shows how many atoms of each element a molecule contains.

10. 8.1 Molecular Formulas

11. 8.1 Molecules and Molecular Changes • Ethane, a component of natural gas, is also a molecular compound.

12. Types of Bonding ? (review) • Chapter 8: Covalent Bonding

13. Sea of electrons model used to explain bonding in metals • Kernel & delocalized mobile valence electrons BONDING

14. Electrostatic attraction of negatively and positively charged ions Can be formed as a result of the transfer of electrons between metal and nonmetal atoms to form cations and anions BONDING

15. BONDING

16. Types of Bonding

17. Bonding in: Na ? NaCl? H2 or Cl2 ? HCl ? H2O ?

18. 8.1 Molecules and Molecular Compounds • Molecules and Molecular Compounds • How are the melting points and boiling points of molecular compounds different from those of ionic compounds?

19. 8.1 Molecules and Molecular Changes • Molecular compounds tend to have relatively lower melting and boiling points than ionic compounds.

20. Practice – properties of ionic and covalent compounds • Go to interactive table on Glencoe site: Physical Properties of ionic and covalent compounds • http://glencoe.mcgraw-hill.com/sites/0078807239/student_view0/chapter9/concepts_in_motion.html#

21. 8.1 Section Quiz. • 8.1.

22. 8.1 Section Quiz. • 1. Compared to ionic compounds, molecular compounds tend to have relatively • low melting points and high boiling points. • low melting points and low boiling points. • high melting points and high boiling points. • high melting points and low boiling points.

23. 8.1 Section Quiz • 2. A molecular compound usually consists of • two metal atoms and a nonmetal atom. • two nonmetal atoms and a metal atom. • two or more metal atoms. • two or more nonmetal atoms.

24. 8.1 Section Quiz • 3. A molecular formula shows • how many atoms of each element a molecule contains. • a molecule's structure. • which atoms are bonded together. • how atoms are arranged in space.