1. Bohr Models are NOT Boring! How to Draw Bohr Diagrams

2. Bohr Diagrams 1)Find the element on the periodic table. 2)Determine the number of electrons--it is the same as the atomic number. 3)This is how many electrons you will draw.

3. Bohr Diagrams Find out which period (row) your element is in. www.chem4kids.com Elements in the 1 st period have one energy level. Elements in the 2 nd period have two energy levels, and so on. 1 2 3 4 5 6 7

4. Bohr Diagrams 1)Draw a nucleus with the element symbol inside. C 2)Write the number of Protons and Neutrons the element has inside the nucleus. Put a + by the P and a little 0 by the N. P + = 6 N 0 = 6 Note: Round mass to nearest 1 when figuring neutrons.

5. The electron shells surrounding the nucleus each hold a particular number of electrons. Shells are named with letters: 1 = K shell = 2 electrons 2 = L shell = 8 electrons 3 = M shell= 8 electrons 4 = N shell= 18 electrons 5-7 = O, P, Q= up to 32 electrons Remember: The outer shell of an atom (no matter what letter) can only hold 8 electrons!

6. Bohr Diagrams 1)Carbon is in the 2 nd period, so it has two energy levels, or shells. 2)Draw the shells around the nucleus. C P + = 6 N 0 = 6

7. Bohr Diagrams 1)Add the electrons. C P + = 6 N 0 = 6 2 e- 2)Carbon has 6 electrons. 3)The first shell can only hold 2 electrons. 4)Write the number of electrons that shell holds and e- for electrons an their charge. 5)How many electrons are in the outer shell?

8. Bohr Diagrams 1)Since you have 2 electrons in the first shell, you need to add 4 more. C P + = 6 N 0 = 6 2)These go in the 2 nd shell. 3)Again, write e- and the number of electrons. 2e- 4e-

9. Bohr Diagrams 1)Check your work. 2)You should have 6 total electrons for Carbon. 3)Only two electrons can fit in the 1 st shell. 4)The 2 nd shell can hold up to 8 electrons. 5)The 3 rd shell can hold 18, but the elements in the first few periods only use 8 electrons. C P + = 6 N 0 = 6 2e- 4e-