2. Where are electrons found? Nucleus Least likely Most likely

3. How much space is between the nucleus and electrons? 1 kilometer away 9 kilometers away 4 kilometers away

4. Bohr’s Model Nucleus 1 st principal energy level can hold 2 e - 3 rd principal energy level can hold 18 e - 2 nd principal energy level can hold 8 e -

5. Drawing Carbon-12 with Bohr’s Model Steps: 1.Find number of neutrons and protons. 2. Find number of electrons. 3. Fill in electrons, beginning with the 1 st energy level.

6. You Try! Fluorine - 19

7. You Try! Aluminum - 27

8. Gallery Walk

9. 13 p + 14 n 0 Help! We’re so vulnerable! Valence electrons

10. Electrons found in the outermost energy level of an atom Electrons found in the outermost energy level of an atom Carbon -12 has 4 electrons in the last energy level... therefore carbon-12 has 4 valence electrons

11. How many valence electrons does Sulfur – 32 have?

12. Cool Trick! 1 6 2 3 4 5 7 8

13. Lewis dot structures When an atom connects with another atom, only the valence electrons are involved. When an atom connects with another atom, only the valence electrons are involved. Lewis dot structures are a way to draw atoms showing only the valence electrons Lewis dot structures are a way to draw atoms showing only the valence electrons Ca

14. Lewis dot structures Used to show valence electrons Used to show valence electrons Start with single electrons on all four sides first before starting to pair up Start with single electrons on all four sides first before starting to pair up N

15. You try Ne C O Cl

16. Bonding potential Unpaired electrons are used in chemical bonds. Unpaired electrons are used in chemical bonds. How many bonds can Nitrogen have? How many bonds can Nitrogen have? 3 unpaired electrons  3 potential bonds 3 unpaired electrons  3 potential bonds N