1. Chapter 5 Atoms and Bonding Section 1 Atoms Bonding and the Periodic Table

2. Do Not Draw

3. I. Valence Electrons and Bonding A.Electron Dot Diagrams 1.Valence electrons are those that are held most loosely. 2.Electron Dot diagrams show only the chemical symbol and the number of valence electrons. Ex. H·

4. 3. In general, the dots are placed by starting on the right side and moving counter clockwise adding one dot at a time. Ne

5. B. Chemical Bonds and Stability. 1. Atoms are more stable when they have 8 valence electrons. 2. Reactions occur in a way that makes atoms more stable. They can either: a. give away (transfer) b. take (gain) c. share 3. A chemical bond is the force of attraction between 2 atoms.

6. II How the Periodic Table Works A.Noble Gases 1. They already have 8 valence electrons (except Helium which is stable with 2) B. Metals 1. Metals get more stable by giving away their electrons so their next shell has 8. 2. Why would lithium be an exception? 3. Lithium’s only other shell can only hold 2 valence electrons. Beryllium too!

7. C. Nonmetals 1. Nonmetals react by gaining or sharing electrons so that they have 8 valence electrons. Except….. D. Hydrogen 1. Hydrogen has only 1 electron so it sits above the alkali family and is very reactive even though it is a nonmetal.