1. Atoms – Review – Lab Book p.88
If you look closely at the tip of a sharpened pencil, you will see that it is made of graphite. Going deeper, graphite is made of carbon atoms. Deeper still, each carbon atom is made of protons, neutrons, and electrons.
Draw and label the nucleus (protons, neutrons) and electrons for the carbon atom above.

2. Complete the following……
Draw a line between the subatomic particle and its charge.
proton no charge
electron positive charge
neutron negative charge
Would the following subatomic particles attract each other or repel one another?
Two protons _____________
Two electrons ____________
A proton and an electron _________

3. Check your answers……..
Draw a line between the subatomic particle and its charge.
proton no charge
electron positive charge
neutron negative charge
Would the following subatomic particles attract each other or repel one another?
Two protons - NO
Two electrons - NO
A proton and an electron - NO

4. Vocabulary –
Find the following term in the Chemical Interactions book and write the definition on page 88 in your lab book……
Element
Isotope
Periodic Table

5. Inside the Box

7. Assignment: Finish the rest of the worksheet and turn it in to your teacher.

8. What is a Bohr Diagram?
A Bohr Diagram is a representation of an atom which places electrons in energy levels (represented by rings) around the nucleus.

9. 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.

10. 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.

11. Energy Levels - can only hold so many Electrons
K – is the 1st energy level around the nucleus This energy level can hold 2electrons.
L - is the 2nd energy level around the nucleus This energy level can hold 8 electrons.
M - is the 3rd energy level around the nucleus This energy level can hold 18 electrons.
N - is the 4th energy level around the nucleus This energy level can hold 32 electrons.

12. Energy Levels

13. C Bohr Diagrams Draw a nucleus with the element symbol inside.
Carbon is in the 2nd period, so it has two energy levels, or shells.
Draw the shells around the nucleus. C

14. C Bohr Diagrams Add the electrons. Carbon has 6 electrons.
The first shell can only hold 2 electrons. C

15. Bohr Diagrams
Since you have 2 electrons already drawn, you need to add 4 more.
These go in the 2nd shell.
Add one at a time -starting on the right side and going counter clock-wise. C

16. C 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.
The 3rd shell can hold 18, but the elements in the first few periods only use 8 electrons. C

17. Bohr Diagrams
Try the following elements on your own: H He O Al Ne K C

18. H Bohr Diagrams Try the following elements on your own: H – 1 electronAl Ne K H

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

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

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

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

23. Bohr Diagrams K Try the following elements on your own: H He O Al Ne
K - 19 electrons K

24. Bohr Diagrams
End of Study Guide. You should know how to draw a Bohr Diagram for the first 20 elements.