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.

2. Why is the Statue of Liberty green?
You probably already know that the Statue of Liberty is made of copper. Why isn’t it the same color as a penny?
How has this lock changed over time?
How are these two processes alike?
ENGAGE: The surface of the Statue of Liberty’s copper skin has chemically combined with oxygen over time to form the blue-green patina. The iron in the lock has combined with oxygen over time to form iron oxide—also known as rust. Both processes occur when one element (a metal) chemically combines with another element (oxygen).
Ask your students to look around the classroom. How many objects can they see that are made of only one element? Probably very few. Look for examples of compounds (like water, salt, or polystyrene) and examples of mixtures (like colas, wood, or even air). Ask the students how they would classify various classroom materials, and why.

3. The periodic table
EXPLORE: Introduce your students to the periodic table, a useful chart of all the known elements. Point out that while most of these elements readily combine with other elements to form compounds, the elements in the last column do not naturally form chemical bonds with other atoms and are almost always found in their pure state. They are known as the noble gases.

4. Molecules and compounds
Time to investigate!
Molecules and compounds
EXPLORE:
Lead the lesson investigation: Molecules and Compounds.
Read the lesson introduction aloud with the class. Emphasize that the properties of a molecule depend on the type of elements present, the number of each element, and the shape in which the elements are arranged.

5. What is the chemical formula?
Determine the chemical formula for each molecule.
EXPLAIN: Use the animation accessed from the multimedia lesson home page to teach students how to find the chemical formula. Use the three molecules in this slide to practice this skill. Students can use the periodic table to find the name and/or the chemical symbol for each element. Remind them to use subscripts to describe the number of atoms of each element in the compound.
The compounds shown are: Water, H2O; Nitrogen, N2; and Butane, C4H10.
Assign the student reading.

6. Shape matters, too!
Glucose and fructose have the same chemical formula, but the atoms are arranged differently. Which molecule has more atoms forming its ring?
While both molecules are simple sugars, your body requires insulin to digest glucose, but not fructose.
EXTEND: Students can work in groups to build models of glucose and fructose using colored gumdrops and toothpicks.

7. Time for Practice! Complete the lesson practice worksheet:
- Chemical formulas
ELABORATE:
Guide students as they complete the practice worksheet.

8. 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.