This lesson is appropriate for children ages 11 and up.
Students first model how increasing levels of carbon dioxide in the air can alter chemical reactions in the ocean water. They will compare the chemical reactions shown on “Normal Ocean Chemistry” mat with “Ocean Acidification” mat. These activities recreate important chemical reactions in the ocean using LEGO® bricks to model the atoms.
After completing the first two activities mats, the students engage with the “Ocean and pH Scale” mat.
This activity is highly recommended to help students understand the consequences of ocean acidification.
Several short activities explain what the pH numbers mean and include the following objectives: reinforcing the essential chemistry concepts for ocean acidification, making predictions for our ocean’s pH in the future, and providing suggestions for what students can do to slow down ocean acidification.
- 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.
- Layout Mat/Atom Key
- Normal Ocean Chemistry Mat
- Ocean Acidification Mat
- Oceans and the pH Scale Mat
- Toxic Mercury in Our Environment Mat
- LEGO Atoms and Molecules Sets (if you don't have these LEGO kits, see below)
For educators planning to teach only the "Understanding Oceans" lessons, you may collect the following fewer number of bricks per student kit:
- 12 red 2x4 bricks (oxygen atoms)
- 4 black 2x4 bricks (carbon atoms)
- 4 grey 2x4 bricks (mercury atoms)
- 1 green 2x4 brick (calcium atom)
- 12 white 1x2 bricks (hydrogen atoms)
Note: "2x4" and "1x2" refer to the number of bumps on top of the LEGO bricks.
Standard LEGO bricks can be used and will serve for our Photosynthesis and Chemical Reactions lessons as well. The Atoms and Molecules Layout Mat shows the recommended LEGO bricks. We chose these bricks because they can be used to illustrate a number of chemical and biological concepts. Their colors match those commonly used in other chemical models, though other colors may be substituted. The layout mat can also be used as an easy clean up tool to check if students have all their bricks.
Building blocks (such as LEGO) can be purchased from toy manufacturers or the LEGO.com website. You might also arrange a LEGO brick donation with your local Parent Teacher Association.
Contact us if you would like to learn how to use the materials at our next workshop or if you would like to inquire about acquiring a classroom set including LEGO bricks.