Bell Ringer 10-22-09 Atomic number tells the number of _________ and ________. Draw an electron dot diagram for K (Potassium). Draw an electron dot diagram for Br (Bromine). What group is Br in? How many valence electrons does Br have? The period tells the number of ______. The group tells the number of _______. Tell me how many atoms are in this compound. CaCl2 Ca = ___ Cl = ___

When atoms form ionic bonds, they transfer electrons. Ionic Bonding When atoms form ionic bonds, they transfer electrons. Gaining electrons Losing electrons

Electron Dot Diagrams He 5. C As 6. Al K 7. Rn Ba 8. Pb

Ionic Bonding Examples K + F 2. Mg + I 3. Be + S 4. Na + O 5. Al + Br

Practice with Compounds Magnesium Chloride = MgCl3 Mg = ___ Cl = ___ 2. Rubbing Alcohol = C3H8O C = ___ H = ___ O = ___ 3. Zinc Chloride = ZnCl2 Zn = ___ Cl = ___ 4. Aluminum Nitrate = Al(NO3)3 Al = ___ N = ___ O = ___ 5. Six molecules of water = 6H2O H = ___ O = ___

Example

Group 1 Alkali metals 1 valence e- + 1 charge Group 2 Alkaline earth metals 2 valence e- + 2 charge Group 13 Boron Fam. 3 valence e- +3 charge Group 14 Carbon Fa. 4 valence e- +4/-4 Group 15 Nitrogen Fam. 5 valence e- -3 charge Group 16 Oxygen Fam 6 valence e- -2 charge Group 17 Halogens 7 valence e- -1 charge Group 18 Noble gases 8 valence e- 0 charge

Look at the charges at the top of the periodic table you just created. What groups elements do you think would like to bond with each other based on their charges? Look at the charges at the top of the periodic table you just created.

Groups 1 and 17 Groups 2 and 16 Groups 13 and 15 Those groups whose valence electrons add together to give you 8 (octet rule).

Crystal Lab

Clean Up W cup up front and pour it out in the sink C cup on back table Salt and Vinegar on side table Magnifying Glasses up front Clean your table with a wipe if it needs it Part of your grade comes from cleaning up!!

Exit Quiz 10-22-09 Atomic number tells the number of _________ and ________. Draw an electron dot diagram for Ca (Calcium). What group is Ca in? How many valence electrons does Ca have? The period tells the number of ______. The group tells the number of _______. Tell me how many atoms are in this compound. H2SO4 H = ___ S = ___ O = ___