The Effect of Acid Rain on Seed Growth
Summary
Using radish seeds, and various dilutions of vinegar, students will conduct an experiment to determine the effect of acid on the seeds. Prior to this lab students will have discussed acid rain and will have also determined the pH of several common substances (baking soda, vinegar, distilled water, ammonia, lemon juice for example). Students will decide what solutions from to test, design the test, create a data table, record data and analyze results.
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Learning Goals
Students will explore the impact of humans on plants by studying the effect of acid on seeds.
Students will plan and conduct a controlled experiment to test a hypothesis about a relationship between two variables.
Key terms: pH, acid rain, pollution
Students will plan and conduct a controlled experiment to test a hypothesis about a relationship between two variables.
Key terms: pH, acid rain, pollution
Context for Use
This lesson is intended for a middle school life science class. This lab will take one class period for background information on acid rain, one class period to set up the lab, several pieces of class for data collection, and then one class period for analysis and conclusions. Teacher prep work includes creating the acid solutions and finding seeds.
Description and Teaching Materials
Prior to lab - Day 1: Discuss acid rain. In lab groups, (3-4 students) have students write down what they have heard about acid rain. After approximately 3 minutes, have students share one thought with their group. Taking turns, have the students share all of their thoughts with the group. Once all groups have shared, have a class discussion. Ask each group to give one thought, and record on the board. Once all groups have shared all of their thoughts, discuss that maybe not all shared thoughts are accurate. Lead into experimentation at this point.
Day 2: Determining acids
Prior to class, prepare the following solutions and place into labeled bottles:
Baking soda (dissolve 4 tablespoons of baking soda into 500 ml of distilled water) This makes 500 ml of solution
lemon juice
Ammonia
Tap water
Distilled water
vinegar
Working in groups (2-4 people), determine the pH of each solution. Determine if the solution is an acid or base.
Day 3: Acid Rain lab
Prior to class - Prepare the following acid solutions and place in labeled bottles
100% Vinegar - 100 ml vinegar
20% Vinegar - 20 ml vinegar and 80 ml distilled water
5% Vinegar - 5 ml vinegar and 95 ml distilled water
1% Vinegar - 1 ml vinegar and 99 ml distilled water
0% Vinegar (water) - 100 ml distilled water
Materials:
seeds (approximately 30 seeds per group) Radish seeds work great
petri plates (3 per group)
Paper towels for the bottom of the petri plates
Acid solutions
Discuss the question to be studied - effect of acid rain on seed growth
In lab groups (2-4 students) have students discuss their hypothesis and record.
Have each group determine the procedure they plan to follow:
Be sure to discuss the importance of keeping all the variables the same, except the percentage of vinegar. For example:
What 3 solutions to use? (be sure all the solutions are chosen by groups)
How much of each solution to use?
How many seeds?
How will the seeds be measured?
Have each group design a lab table to record their data.
Once the procedure has been determined and checked by the teacher, have each group set up their experiment.
Day 4 - 10: Allow time for students to take measurements and record data.
Last Day: Have students record the final results and conclusions.
On the board - make a large data table and have students fill their groups results. What seeds germinated, and growth.
Discuss class results.
Day 2: Determining acids
Prior to class, prepare the following solutions and place into labeled bottles:
Baking soda (dissolve 4 tablespoons of baking soda into 500 ml of distilled water) This makes 500 ml of solution
lemon juice
Ammonia
Tap water
Distilled water
vinegar
Working in groups (2-4 people), determine the pH of each solution. Determine if the solution is an acid or base.
Day 3: Acid Rain lab
Prior to class - Prepare the following acid solutions and place in labeled bottles
100% Vinegar - 100 ml vinegar
20% Vinegar - 20 ml vinegar and 80 ml distilled water
5% Vinegar - 5 ml vinegar and 95 ml distilled water
1% Vinegar - 1 ml vinegar and 99 ml distilled water
0% Vinegar (water) - 100 ml distilled water
Materials:
seeds (approximately 30 seeds per group) Radish seeds work great
petri plates (3 per group)
Paper towels for the bottom of the petri plates
Acid solutions
Discuss the question to be studied - effect of acid rain on seed growth
In lab groups (2-4 students) have students discuss their hypothesis and record.
Have each group determine the procedure they plan to follow:
Be sure to discuss the importance of keeping all the variables the same, except the percentage of vinegar. For example:
What 3 solutions to use? (be sure all the solutions are chosen by groups)
How much of each solution to use?
How many seeds?
How will the seeds be measured?
Have each group design a lab table to record their data.
Once the procedure has been determined and checked by the teacher, have each group set up their experiment.
Day 4 - 10: Allow time for students to take measurements and record data.
Last Day: Have students record the final results and conclusions.
On the board - make a large data table and have students fill their groups results. What seeds germinated, and growth.
Discuss class results.
Teaching Notes and Tips
Assessment
The assessment would be turning in the lab report created in the process of doing the lab.
Standards
7.1.1.2 Conduct a controlled experiment
7.4.41 Human activity can change ecosystems
7.4.41 Human activity can change ecosystems