Additional Teacher Lessons
Below are supplementary lessons to use with your students.
Sensational Renewables
Biogas is a renewable energy source produced by the fermentation of organic matter.
Materials
Sugar
Yeast
Thermometer
Warm Tap Water
Two snack-size, zipper bags
Combine 1 teaspoon of sugar and 1 teaspoon of yeast in the bag. Add 1/4 cup of warm water (approximately 104 F) and seal the bag, removing as much air as possible. Mix the contents of the bag gently. Start a timer. What happened after 20 minutes? The sugar is a plant-based biomass that is “fuel” metabolized by the yeast. How would the experiment differ if you used another form of biomass, like corn meal?
Electrolysis in a Cup
Electricity can be used to separate hydrogen and oxygen atoms in water, so the hydrogen gas can be used as fuel. Try this process called electrolysis!
Materials
9-volt battery
small, clear cup
1/2 teaspoon baking soda or salt
2 pencils, sharpened on both ends (copper wire or a straightened paper clip can replace one or both pencils)
3×5 inch index card
Fill the cup half full with water and add the salt or soda. Push the pencils through the card about an inch apart. Put one point of each pencil in the water and the other point on the terminals of the battery. Observe what happens. Are the results the same for both pencils? How can you explain the difference?