Bohr models are used to predict an element's reactivity by examining its valence electrons, which are the electrons in the outermost energy level. To draw a Bohr model, you draw the nucleus and write the number of protons and neutrons, then draw energy levels and fill them with electrons in pairs according to set rules about how many electrons each level can hold. The document then provides examples of drawing Bohr models for various elements by first determining protons, neutrons, and electrons, and using that information to draw the model.

1. Drawing Bohr ModelsDrawing Bohr Models

2. Bohr ModelsBohr Models
1.1. Bohr models are used to predictBohr models are used to predict
reactivityreactivity in elements.in elements.
2.2. Reactivity refers toReactivity refers to how likely anhow likely an
element is to form a compoundelement is to form a compound withwith
another element.another element.
3.3. When looking at Bohr models, we look atWhen looking at Bohr models, we look at
itsits valence electronsvalence electrons (the electrons on(the electrons on
the last energy level) to determinethe last energy level) to determine
reactivity.reactivity.

3. Drawing Bohr ModelsDrawing Bohr Models
1.1. Draw theDraw the nucleusnucleus..
2.2. Write the number ofWrite the number of neutronsneutrons and the numberand the number
ofof protonsprotons in the nucleus.in the nucleus.
3.3. Draw the firstDraw the first energy levelenergy level..
4.4. Draw theDraw the electronselectrons in the energy levelsin the energy levels
according to the rules below. Make sure youaccording to the rules below. Make sure you
draw the electrons indraw the electrons in pairspairs..
5.5. Keep track of how many electrons are put inKeep track of how many electrons are put in
each level and the number of electrons left toeach level and the number of electrons left to
use.use.

4. Rules for Energy LevelsRules for Energy Levels
1.1. Level 1 (closest to the nucleus) can holdLevel 1 (closest to the nucleus) can hold
a maximum ofa maximum of 2e2e..
2.2. Level 2 can hold a max ofLevel 2 can hold a max of 8e8e..
3.3. Level 3 can hold a max ofLevel 3 can hold a max of 18e18e..
4.4. Level 4 can hold a max ofLevel 4 can hold a max of 32e32e..
You must fillYou must fill one levelone level before going on tobefore going on to
draw the next level!draw the next level!

5. Guided PracticeGuided Practice
In order to draw Bohr models of these elements, youIn order to draw Bohr models of these elements, you
must first determine the number of protons, neutrons,must first determine the number of protons, neutrons,
and electrons. Once you have found this information,and electrons. Once you have found this information,
follow the directions to draw your model.follow the directions to draw your model.
6
C
Carbon
12.011
6 6 6
2
4
Protons: _____ Neutrons: _____ Electrons: ______
How many energy shells will this have? ____
How many valence (outer) electrons does this element have? ____
Bohr Model:

6. Guided PracticeGuided Practice
16
S
Sulfur
32.066
Protons: _____ Neutrons: _____ Electrons: ______
How many energy shells will this have? ____
How many valence (outer) electrons does this element have? ____
Bohr Model:
16 16 16
3
6

7. Guided PracticeGuided Practice
Protons: _____ Neutrons: _____ Electrons: ______
How many energy shells will this have? ____
How many valence (outer) electrons does this element have? ____
Bohr Model:
3
Li
Lithium
6.941
3 4 3
2
1

8. Guided PracticeGuided Practice
Protons: _____ Neutrons: _____ Electrons: ______
How many energy shells will this have? ____
How many valence (outer) electrons does this element have? ____
Bohr Model:
10
Ne
Neon
20.180
10 10 10
2
8

9. Guided PracticeGuided Practice
Protons: _____ Neutrons: _____ Electrons: ______
How many energy shells will this have? ____
How many valence (outer) electrons does this element have? ____
Bohr Model:
15
P
Phosphorus
30.974
15 16 15
3
5

10. Guided PracticeGuided Practice
Protons: _____ Neutrons: _____ Electrons: ______
How many energy shells will this have? ____
How many valence (outer) electrons does this element have? ____
Bohr Model:
11
Na
Sodium
22.990
11 12 11
3
1