1. Bohr Diagrams
Rules and Directions

2. Bohr Diagram Rules Bohr Diagrams show: Energy Levels: 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 6P 6N CARBON
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

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 6P 6N 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 6P 6N Try the following elements on your own: H He O AlNe 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 2P 2N Try the following elements on your own: H
He - 2 electrons O Al Ne K 2P 2N

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

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

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

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