1. September 13, 2010 Homework Chp 3 study Guide (download) & notes due wed Write a response to “Radioisotopes” essay prompt. You may use your book or other resource for ideas Objectives Use models to review basic chemistry BellRinger Draw an oxygen atom and label: electron, proton, neutron, nucleus, and orbital

2. Atomic Modeling Draw an image similar to transparency on half of paper Use the info in the periodic table to make a helium atom using drawing and beads How many of each subatomic particle do you need? How can you use the periodic table to help? (review atomic # and atomic mass) Draw the atom in your notes What would happen if you altered the #of each particle? Electron=charged ion Proton=new element Neutron= isotope

3. Orbitals How many electrons can fit in each orbital? Practice with C, N, O, and F How does proton # compare with e #? What is the relationship btwn stability of the atom and the number of electrons in the valence shell? How many more e- does each element need to become stable? What happens to the stability of the atom as you move left to right on the periodic table? (take notes on p. table) Electronegativity increases Which elements are the most stable? Which are the most reactive?

5. Learning Check What determines the chemical behavior of an atom? Give an example of two atoms that have different chemical behaviors and explain the cause of their difference

7. Ionic Molecules Draw a second atomic model on the paper Create an fluorine atom (7) and an hydrogen atom What can you say about the stability of each atom? What would make each one more stable? What type of bond is being formed? Move the beads to make each one stable Draw a before and after in their notes Do the same with LiCl, MgO, and BeS 3 17 12 6 4 16 (atomic numbers)

8. Ionic Bonds Label cation and anion for each molecule (cations-Li, Mg, Be; anions Cl, O, S) Look at trends in p. table…which elements tend to become neg? Why? Positive? Why? (relate back to electronegativity) Which columns combine to form ionic bonds? Why? Why don’t all of the elements form ionic bonds? (not enough e.neg to steal or too much e.neg to give away electrons) So what do those atoms do?

9. Learning Check What conditions must be present in order form an atom to form an ionic bond with another atom? Using the periodic table and your notes, provide an example of 2 atoms that would likely form an ionic bond (you can’t use one we did in class). Explain which element is the cation and which is the anion Describe how the electronegativity of each allows it to react with the other atom

10. September 14, 2010 Homework Complete Chp 3 Study guide and notes Objectives Use models to review basic chemistry Peer edit a free response essay using a rubric BellRinger What do atoms that cannot form ionic bonds do to become stable?

11. Covalent bonding (Students will need to be able to overlap their atomic models) Make two hydrogen models Will these form an ionic bond? Why not? What is their only option? (share the e-) Slide the models together, overlapping the shell so that they share the 2 e- Draw and explain the process in your notes Practice with CH4 and NH3 Try double bonds with paper models Show how O2 and CO2 covalent bonding can be demonstrated with candy models

12. Learning Check Explain how valence electrons influence molecular bonding Explain how electronegativity influences molecular bonding

13. Hydrogen Bonding Make CH4, C2H6, C3H8, O2, and CO2 candy models How many bonds can H make? O? C? Make 2 H2O, and 1 each H2, O2, NH3, and CH4 Which molecules are symmetrical? Polar vs. Non polar? Relationship btwn symmetry and polarity? Relationship btwn e.negativity and polarity? Arrange the H2O molecules according to polarity Draw a dotted line btwn neg and pos poles to show H bonding Ethane propane

15. Learning Check Complete the “Comparing molecular bonds” handout

16. Free Response Essay Use the provided rubric to grade a classmates essay. Give them a score out of 10 based on the guidelines provided.

17. Summary What seems to be the most important things to remember when writing free response essays? Homework Complete Chp 3 Study guide and notes