1. Objective Utilize & apply the Periodic Table to diagram Bohr Models and Lewis Dot Diagrams. Main Ideas 1. Energy Levels 2. Bohr Modeling 3. Valence Electrons 4. Octet Rule 5. Lewis Dot Diagrams Bohr Modeling & Lewis Dot Diagrams IAN pg. 23 Don't find fault, find a remedy. - Henry Ford

2. I. Bohr Modeling A. Atomic number = protons & electrons A neutral atom has equal numbers of each. B. Electrons found in energy levels or shells. 1. Energy levels or shells hold a maximum number of electrons.

3. Energy Level Total # ofTotal Or Shell electrons / shell Combined 1 2 (1)2 2 8 (2)10 3 18 (3)28 4 32 (4)60 5 32 (5)92 6 22+ (6)114+ Sublevels: s,p,d,f,g,h Indicates the number of electrons/energy level

4. Chemical Symbol: Na (Sodium) At #_11_ At Weight_23_ Protons = _11_ Electrons _11_ Neutrons = _12_ (At W – At #) Energy Shells or Levels = _3_ (See Energy Level Chart IAN pg. 53) 11P 12N Bohr Model Example

5. II. Lewis Dot Structures A. “Dot Models” are used to represent Valence Shell electrons B. Gilbert Newton Lewis 1875-1946 American Chemist discovered covalent bond

6. C. The electrons in the outer most energy level are called valence electrons. D. Atomic Stability depends on filling the valence shell with electrons =Octet Rule 1. This is why specific atoms will bond with other atoms. Ex. H 2 O

7. Periodic table groupValence electrons Group 1 (I) (alkali metals)alkali metals 1 Group 2 (II) (alkaline earth metals)alkaline earth metals 2 Groups 3-12 (transition metals)transition metals ******* Group 13 (III) (boron group)boron group 3 Group 14 (IV) (carbon group)carbon group 4 Group 15 (V) (nitrogen group)nitrogen group 5 Group 16 (VI) (chalcogens)chalcogens 6 Group 17 (VII) (halogens)halogens 7 Group 18 (VIII or 0) (noble gases)noble gases 8** Think of Valence electrons as “free electrons” They are “free” to move or free to be shared.

8. Groups - Review Each column is called a “group” Each element in a group has the same number of electrons in their outer energy level. Except for He, it has 2 electrons The electrons in the outer energy levels are called “valence electrons”

9. 1. Write the element symbol. 2. Locate the group (1 – 8) This is the # of valence electrons. 3. Follow this diagram for placing electrons as “Dots” in order. Copy this down E.Drawing Lewis Dot Structures

10. IaN pg. 22 Periodic Table of Elements Handout. Glue Down!