ABOUT THE UNDERSTANDING OCEANS LESSON
This lesson is appropriate for children ages 11 and up. Understanding Oceans has students model ocean acidification using LEGO® bricks as atoms. Students also learn more about pH and mercury biomagnification in food webs. Students first model how increasing levels of carbon dioxide in the air can alter chemical reactions in the ocean water. Several short activities explain what the pH numbers mean, make predictions for our ocean’s pH in the future, and provide suggestions for what students can do to slow down ocean acidification.
TEACHING THE UNDERSTANDING OCEANS LESSON
The overviews below should help to teach this lesson. Students should already be familiar with the concept of LEGO bricks as atoms, having completed one of the previous topics (Chemical Reactions, Photosynthesis, and/or Understanding Air). Instructors need to add their own age-appropriate information and sources about the effects of mercury toxicity and healthy dietary consumption of fish.
- Students will first model a normal ocean to observe the chemical reactions that occur in the ocean.
- Next, the students will model the chemical reactions that produce ocean acidification. The initial number of carbon dioxide molecules in the air above the water will be increased to observe what happens. A greater number of carbon dioxide molecules will be absorbed by the ocean.
- The increased carbon dioxide in the water has consequences now. The increase in free H atoms can make it too difficult for sea creatures to build chalk for their shells.
- In the first activity, students work with white LEGO bricks that represent H atoms. In this way, students begin to visualize that the ‘H’ in pH as referring to the number of free hydrogens. It is not necessary to have younger students relate the pH numbers to negative exponents, however the negative log scale is given in the small inset as way for a teacher point out the connection.
- Seeing the pH numbers range from 0 to 14 may be helpful for some students. The other activities on the mat have additional objectives-- such as making predictions for our ocean’s pH in the future, and providing some actions to help slow ocean acidification.
- Mercury is a poison. This lesson focuses on how mercury moves through the environment and how the mercury may accumulate in the fish humans eat.
- Mercury sources contribute both to the levels of mercury in air and in water all around the planet.
- Microorganisms found in soil take elemental mercury and create methylmercury molecules.
- The biomagnification of methylmercury in fish modeled. This example provides a hands-on activity, reinforcing the concept of food chains in the ocean.
MOLECULE SET MATERIALS
You can make your own Molecule Sets by visiting our webpage: Information for Edgerton Center Molecule Sets. We are no longer able to sell Molecule Sets, unfortunately.
The following LEGO bricks are the minimum required (per kit/2 students) for the Understanding Oceans Lesson:
- 12 red 2x4 bricks
- 4 black 2x4 bricks
- 4 grey 2x4 bricks
- 1 green 2x4 brick
- 12 white 1x2 bricks
NOTE: "2x4" and "1x2" refer to the number of bumps on top of the LEGO bricks.
Understanding Oceans Mats (per kit/2 students):
- Atom Key/Layout Mat*
- Normal Ocean Chemistry Mat
- Ocean Acidification Mat
- Oceans and the pH Scale Mat
- Toxic Mercury in Our Environment Mat**
*NOTE: The Atom Key/Layout Mat is the only mat included with the Molecules Set. Print out the other mats in color at 100% size on 11"x17" paper or in halves on 8.5"x11" paper.
**NOTE: The Toxic Mercury in Our Environment Mat is optional, and can be completed with or without the rest of the lesson. It must be printed in thirds on 8.5"x11" paper.
Central Concepts: Energy resources are used to sustain human civilization. The amount and accessibility of these resources influence their use and their impact on the environment. 2.1 Recognize, describe, and compare renewable energy resources (e.g., solar, wind, water, biomass) and nonrenewable energy resources (e.g., fossil fuels, nuclear energy).
2.2 Describe the effects on the environment.
LEGO®, the LEGO logo, and the brick and knob configurations are trademarks of the LEGO group, used here with permission. ©MIT. All rights reserved.