The Copper Basin Problem: Teacher Guide Lesson 5

The Effects of Acid Rain on the Germination of Seeds

Objectives:

• To test the effects of acid rain on organisms.
• To test air samples for sulfur dioxide.
• To relate the test results to the Copper Basin issues.

Materials:

• Goggles
• Ruler
• Petri dishes
• Graph paper
• Wax pencil
• Water solutions, pH 2-7
• Paper towels
• Rainwater
• Scissors
• Seeds (radishes germinate quickly)

Optional materials: Air sampling pump, Sulfur Dioxide Test Kit

Procedure:

1. One of the issues in the Copper Basin is acid rain that is caused by the formation of sulfur dioxide in the roasting and smelting processes. This has long term effects on the environment and impacts the land for years. Students developed a simple experiment to test the effect of an acidic solution on the germination of seeds. They originally wanted to test the effects on plants used in revegetation efforts, but did not have the time necessary to see any visible effects. They were able to apply the results they observed in other instances in which acid rain or acid solutions get into the soil.
2. Radish seeds were placed into petri dishes and watered with solutions of different pH. Results were checked daily for evidence of germination.
3. Students in one of the groups read about the relationship between sulfur dioxide in the air and the production of acid rain. The Copper Basin video also talked about high levels of sulfur dioxide remaining in the air. One group decided to test air samples for levels of sulfur dioxide and related its results to the pH of rainwater samples. Through the Internet, students exchanged data with other students who performed similar investigations and confirmed the correlation between the presence of sulfur dioxide and acid rain.
4. Maps of acid rain distribution can be used to help summarize both activities.
5. Students should relate the results of the seed germination lab to the original issues raised in the Copper Basin video.