TEACHER MASTER Chemistry - Science 9
Bohr Models
In this set of notes we will cover:
- Draw a Bohr model of each atom up to atomic number 20
Ø Recommended time required for presentation of this set of notes:
o 45 minutes to 60 minutes depending on the group
Ø Materials Needed:
Ø Special Notes:
o By the end of the lesson students should find Bohr diagrams relatively simple. Remind them to practice a few for homework as they are easy to forget how to do.
TEMPLATED NOTES BEGIN ON NEXT PAGE SO THAT THEY CAN EASILY BE PRINTED OR COPIED ONTO AN OVERHEAD TRANSPARENCY
Bohr Models NAME ______
DATE ______
In this set of notes we will cover:
- Draw a Bohr model of each atom up to atomic number 20.
Reading the Periodic Table
For the first 20 elements of the periodic table you can “read” how the electrons are arranged around the nucleus.
Rows represent levels (or layers) of the orbital.
Columns represent each electron added.
1st Row:
The first energy level can only hold two electrons. So there are only two elements in the first row (hydrogen and helium).
2nd Row:
The second energy level can hold eight electrons (2 columns + 6 more columns). So there are eight elements in the second row. Here are the first three:
Bohr Models
Instead of continuing to draw all these circles a Bohr diagram simplifies things for us. A Bohr diagram just shows the nucleus and indicates how many electrons are in each level.
After figuring out how many electrons an atom has count out how many are in each layer. Remember: the first layer can hold two electrons. The second and third can hold eight.
If you forget … just count the number of elements in each row.
Lithium Oxygen
Berylium Flourine
Boron Neon
Carbon Sodium
Nitrogen
You try a few
Complete the following Bohr Diagrams:
Magnesium
Calcium
Chlorine
Fluorine
Hydrogen
You will need to be able to draw or identify the Bohr diagrams for the first 20 elements.
Quiz Next day: Bohr Model – first 20 elements
L08C2- Notes - Teacher Master - Bohr Model.doc