1. To the teacher:
This CPO Science PowerPoint presentation is designed to guide you through the process of presenting the lesson to your students. The presentation uses a 5-E teaching model: Engage, Explore, Explain, Elaborate, and Evaluate.
The PowerPoint Slide notes indicate where you may want to bring in various lesson elements such as quizzes, readings, investigations, animations, and practice materials. Additional science background information is provided in the slide notes where appropriate. You can view these notes by selecting “View,” then “Normal.” You will see the notes pane at the bottom of the PowerPoint workspace. Additionally, the slide notes are available as a separate document, accessible from the lesson home page.
The slides that follow are intended for classroom use.
About the slide notes:
The slide notes for this presentation are available in a separate document that you can print and look at while you use the slides. You can access the slide notes document from your teacher lesson home page.
Enjoy the lesson!

2. What is inside an atom?
If you crush wintergreen candy with your teeth, blue sparks jump out of your mouth! You can see the effect even better if you crush one of the candies with a pair of pliers in a dark room.
In order to understand why the sparks appear, you must know what is inside an atom. After completing this module, do an internet search on triboluminescence to find out why the candy sparks when you crush it.
ENGAGE:
If possible, take students into a dark room to demonstrate this effect. Triboluminescence occurs when mechanical energy (from crushing the candy) causes some electrons in atoms that make up the candy’s sucrose and wintergreen oil molecules to move up a higher energy state. As the electrons fall back down, they release some of this energy in the visible portion of the electromagnetic spectrum. You can also observe triboluminescence if you clap two quartz rocks together or pull a strip of masking tape away from its roll.

3. Time to investigate!
Complete the lesson investigation: Building the Elements
EXPLORE:
Lead the lesson investigation: Building the Elements

4. Three particles make up all atoms.
Protons have positive (+1) charge. They are found in the nucleus of every atom.
Neutrons have zero charge. They are also found in the nucleus of every atom except hydrogen.
Electrons have negative (-1) charge. They are found in an area outside the nucleus known as the electron cloud.
EXPLAIN: Assign the student reading. Review the locations and charges of the three subatomic particles.

5. The size and structure of an atom
The overall size of an atom is the size of its electron cloud.
If an atom were the size of a football stadium, the nucleus would be the size of a pea, and the electron cloud would be like a small swarm of gnats buzzing around the stadium at high speed.
EXPLAIN: Help students visualize the relative volume occupied by the nucleus vs. the electron cloud. If possible, take students out to your school football field so that they can picture the relative sizes in the analogy above. This helps drive the point home!

6. Where is most of an atom’s mass?
A proton has 1,836 times as much mass as an electron.
A neutron has about the same mass as a proton.
More than 99% of an atom’s mass is in the nucleus.
EXPLAIN: Use the graphic to help students visualize the difference between a proton and an electron’s mass.

7. Summary: the structure of an atom
EXPLAIN: Help students recognize how small an atom is. Point out the tiny masses in the table above.

8. Time for Practice! Complete the lesson practice activity:
Structure of the atom
You will need to know what these words mean: atomic number mass number isotope
Review your student reading for help!
ELABORATE: Introduce students to the concepts of atomic mass, atomic number, and isotopes. The lesson practice activity gives students an opportunity to explore these concepts so that they can find information about an atom’s internal structure from its placement on the periodic table. Use the periodic table animation accessed from the multimedia lesson home page to increase student comfort level with the information found on the periodic table.

9. Show what you know!
Try the lesson’s interactive quiz, or complete a quiz that your teacher can print out for you.
Hint: You might want to review your lesson reading piece one more time before trying the quiz.
EVALUATE:
Print out the 10-question quiz for students to complete, or have students work individually at computers to complete the interactive quiz they can access from the multimedia lesson home page.