1. Do Now Copy the following cart into your notes.
Fill in the “what you know” column with anything you know about atoms.
- (This knowledge can come from our last unit on matter or from previous knowledge.)
Fill in the “what you want to know” column.
What you know K
What you want to know W
What you learned L

2. Agenda “Do Now” (5 minutes) Think, Pair, Share (5 minutes)
Unit Map (10 minutes)
Notes – atomic model (15 minutes)
Group activity (10 minutes)
Exit Ticket (5 minutes)

3. Unit 2: Models that have changed In & around the nucleus
Protons, neutrons, & electrons
Models that have changed
In & around the nucleus
Relative mass and charge
Atoms, ions, and isotopes
Mass #, atomic #, and charge

4. What is an Atom? The basic building block of all matter.
The smallest unit of matter.

5. What are the parts of an atom?
Atoms are made of three subatomic particles
“Sub-” is a prefix meaning “beneath” or “under”
“atomic” refers to the atom
The three subatomic particles are:
Protons
Neutrons
Electrons

6. What does an atom look like?

7. What does an atom look like?
Protons and neutrons are found in the center of the atom in the tightly packed nucleus.
Electrons are found far away orbiting the nucleus.
99.999% of the atom is empty space.

8. If the nucleus where the size of a marble, the whole atom would be the size of a football stadium.

9. Group Activity – 6 minutes
Work quietly with the person next to you to develop another model for the atom
(example: marble in a football stadium)
Write down your group’s model in your notes
Identify what objects in your model represent the 3 subatomic particles (protons, neutrons, electrons)

10. Checks for Understanding
What are the three subatomic particles?
What does “sub-” mean?
Where are protons located?
Where are neutrons located?
Where are electrons located?
How much of the atom is actually empty space?
What is the nucleus?

11. Homework Directions Draw a picture of the model you just created.
Label the 3 “subatomic particles”
Write a 5-sentence paragraph that explains why your model is a good representation of the atom.

12. Exit Ticket - What parts does it have?
On a scrap sheet of paper (to be turned in), describe the structure of an atom.
- What parts does it have?
- Where are all those parts located?
- What does the atom look like?