Bohr Diagrams

1. Bohr Diagrams Rules and Directions

2. Bohr Diagram Rules • Bohr Diagrams show: • The Nucleus: • # Protons • # Neutrons • The “Energy Levels” or “Shells”: • Hold Electrons • Energy Levels: • 1st energy level can hold 2 electrons • 2nd energy level can hold 8 electrons • 3rd energy level can hold 18 electrons • 4th energy level can hold 32 electrons • An energy level is considered “full” if it has 8 in it (OCTET RULE)

3. Bohr Diagrams Find your element on the periodic table. Determine the number of electrons – it is the same as the atomic number. This is how many electrons you will draw.

4. Bohr Diagrams • Find out which period (row) your element is in. • Elements in the 1st period have one energy level. • Elements in the 2nd period have two energy levels, and so on. • Remember, an “Energy Level” is also called a shell.

5. Bohr Diagrams • Calculate the number of Protons, Neutrons, and Electrons in the Carbon atom • Draw a nucleus showing the number of protons and neutrons the element has. • Carbon is in the 2nd period, so it has two energy levels, or shells. Draw the 2 shells around the nucleus. 6P 6N CARBON P: N: E: 6 6 6

6. Bohr Diagrams • Add the electrons. Carbon has 6 electrons to place on the shells. • The first shell can only hold 2 electrons, so place 2 there. • The second shell can hold 8 electrons, so place the other 4 there. (6 electrons – 2 electrons = 4 electrons) 6P 6N

7. Bohr Diagrams • Check your work. • You should have 6 total electrons for Carbon. • Only two electrons can fit in the 1st shell. • The 2nd shell can hold up to 8 electrons. 6P 6N

8. Bohr Diagrams Try the following elements on your own: • H • He • O • Al • Ne • K 6P 6N

9. Bohr Diagrams In your notes, try the following elements on your own: • H – 1 electron • He • O • Al • Ne • K 1P 0N

10. Bohr Diagrams Try the following elements on your own: • H • He - 2 electrons • O • Al • Ne • K 2P 2N

11. Bohr Diagrams Try the following elements on your own: • H • He • O - 8 electrons • Al • Ne • K 8P 8N

12. Bohr Diagrams Try the following elements on your own: • H • He • O • Al - 13 electrons • Ne • K 13P 14N

13. Bohr Diagrams Try the following elements on your own: • H • He • O • Al • Ne - 10 electrons • K 10P 10N

14. Bohr Diagrams Try the following elements on your own: • H • He • O • Al • Ne • K - 19 electrons 19P 20N

15. Bohr Diagrams – Ions! C 4- P: N: E: Draw the Bohr Diagram with the above information! 6 6 10 (6+4) 6P 6N

16. Bohr Diagrams – Ions! In your notes, try the following elements on your own: • O 2- • Al 3+ • K + 6P 6N

17. Bohr Diagrams – Ions! O 2- -10 Electrons 8P 8N

18. Bohr Diagrams – Ions! Al 3+-10 Electrons 13P 14N

19. Bohr Diagrams – Ions! K +-18 Electrons 19P 20N

20. Bohr Diagrams - Isotopes! Carbon – 14 P: N: E: Draw the Bohr Diagram with the above information! 6 8 (14-6) 6 6P 8N

21. Bohr Diagrams - Isotopes! In your notes, try the following elements on your own: • Hydrogen -2 • Helium - 6 • Oxygen -15 • Aluminum - 30 • Neon -19 • Potassium - 42 6P 8N

22. Bohr Diagrams - Isotopes! In your notes, try the following elements on your own: Hydrogen -2 – P:1 N:1 E:1 1P 1N

23. Bohr Diagrams - Isotopes! In your notes, try the following elements on your own: Helium - 6 – P:2 N:4 E:2 2P 4N

24. Bohr Diagrams - Isotopes! In your notes, try the following elements on your own: Oxygen -15 – P:8 N:7 E:8 8P 7N

25. Bohr Diagrams - Isotopes! In your notes, try the following elements on your own: Aluminum - 30 – P:13 N:17 E:13 13P 17N

26. Bohr Diagrams - Isotopes! In your notes, try the following elements on your own: Neon -19 – P:10 N:9 E:10 10P 9N

27. Bohr Diagrams - Isotopes! In your notes, try the following elements on your own: Potassium - 42 – P:19 N:23 E:19 19P 23N