3. Electrons and Energy Levels  Electrons are found in energy levels Energy LevelCapacity Level #12 Electrons (2 valence) Level #28 Electrons (8 valence) Level #318 Electrons (8 valence) Level #432 Electrons (8 valence)

4. Energy Level Diagram for Fluorine  In the first orbit, there are 2 electrons.  In the second orbit, there are 7 electrons.  In the third orbit, there are no electron

5.  Diagrams for Hydrogen and Carbon

6. Valence electronsValence electrons  The electrons in the outermost energy level of an atom.  The number of valence electrons vary from 1 to 8.  These are the electrons that participate in chemical bonding.

7. Know the group know the valence electrons!  Use the periodic table to find the number of valence electrons quickly, or for elements that we do not know how to draw...  Elements belonging in Group 1 (IA) ( H, Li, Na, K ) 1 valence electron  Elements belonging in Group 2 (IIA) ( Be, Mg, Ca ) 2 valence electrons  Elements belonging in Group 3 (IIIA) (B, Al, Ga,) 3 valence electrons

8. Know the group know the valence electrons!  Elements belonging in Group 4 (IVA) (C, Si) have 4 valence electrons  Elements belonging in Group 5 (VA) (eg - N, P) have 5 valence electrons  Elements belonging in Group 6 (VIA) (eg - O, S) have 6 valence electrons  Elements belonging in Group 7 (VIIA) (eg - F, Cl) have 7 valence electrons  Elements belonging in Group 8 (VIIIA) (eg – He, Ar) have 8 valence electrons

9. Electron dot diagrams  Only show VALENCE electrons  Element symbol goes in the middle  One dot for each valence electron around the symbol  Starting from the top, and moving clockwise, one dot goes around each side (4 sides)  When a dot (electron) is around all 4 sides, fill in a second, again starting from the top.