TEACHER RESOURCES

State Standards | Classroom Demonstrations

State Standards

GRADE EIGHT

5. Chemical reactions are processes in which atoms are rearranged into different combinations of molecules. As a basis for understanding this concept:

a. Students know reactant atoms and molecules interact to form products with different chemical properties.

GRADES NINE THROUGH TWELVE: PHYSICS

Electric and Magnetic Phenomena

5. Electric and magnetic phenomena are related and have many practical applications. As a basis for understanding this concept:

a. Students know how to predict the voltage or current in simple direct current (DC) electric circuits constructed from batteries, wires, resistors, and capacitors.

b. Students know how to solve problems involving Ohm's law.

d. Students know the properties of transistors and the role of transistors in electric circuits.

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Classroom Demonstrations

1. Using the voltmeter, measure the conductivity in your partner's skin. Have your partner do jumping jacks for 3 minutes. Then measure the conductivity in their skin. Why is there an increase? How does this apply to someone who is not telling the truth? How accurate is this for determining whether someone is telling the truth or not?

2. Skin cancer is a rising threat. More and more people are becoming ill from exposure to the sun. How much are we truly being protected by wearing clothing or staying out of the sun?

   Using Ultra-violet polymer beads, choose 5 types of commonly worn fabrics. Hypothesize how much sun protection they offer. Place beads under these fabrics (ie. clothing) and expose to the sun. What can you conclude about your results. Choose 5 environments (ie. In the sun, in the shade of a building, indoors with open windows, by a large tub of water, in the shade of a tree, under overcast skies). Hypothesize how much sun protection they offer. Place beads in these environments. What can you conclude about your results?

   What conclusions or recommendations can you make about sun exposure? How could these beads be used to help improve our awareness of sun exposure?

   Order Ultraviolet Beads: Product # IN49341

3. Make your own optic sensor that indicates whether a liquid is a base (not an acid). You'll need 1/3 cup alcohol, 1/4 teaspoon turmeric powder, coffee filter paper, 1 bowl, 1 spoon, 1 cookie sheet and a resealable plastic bag. Stir the alcohol and turmeric powder in a bowl. Dip the coffee filter paper in the turmeric solution. Place the filter on a cookie sheet to dry. Cut the dried paper into strips about 1" x 4" and store in the plastic bag. The strips are yellow. When exposed to a base, they turn red.

   To test: Place 1/2 teaspoon of baking soda in a cup with 1/2 teaspoon of water. Mix. Dip the turmeric paper in the cup. Is baking soda a base or an acid?

   What other liquids or dissolved solids could you test with this paper? Why is it important to test for ph in certain liquids? Why is it significant to research for different optic or chemical sensors? What applications can these sensors be used for in real-life situations?

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Lesson developed by the students of Theresa Gilly's 2001-2 chemistry class at High Tech High: Amanda Converse-Rath, Jay Fox, Scott Ritzma and Lin Tran.