Part of Lesson Plan: Nitrogen Cycle in Agriculture- Jennifer Terpstra

Activity Overview / Details

Provide student lab groups (I have 4 in a group) with sets of Lego blocks. Make sure each set has the same number of sizes and colors of blocks. For example, if one group has 8 blue, 1-inch blocks, then all groups must have the same. I like to put sets together in bags before hand. As a teacher, there is complete freedom as far as the blocks put in each bag, just as long as the sets are the same. Begin by asking the students to construct anything of their choosing, but they have to use all of the blocks in the bag. They can choose anything as long as it is a structure of something common, like a flower or car, not a mythical creature. Give them only 2 minutes, otherwise they will waste time playing rather than constructing. Quickly have each group hold up their structure and tell the class what they have made. Explain to students that these blocks represent matter. Now give students two more minutes to make a different structure, following the same rules as before. Explain to students that much like molecules (made up of atoms, the basic form of matter), these blocks can come apart and be joined back together to make something else; the atoms within molecules can be changed to make another molecular structure, but the basic elements are unchanged, even though the structure itself has changed. Then give students another minute to make the same structure as before, but switch some pieces and put them in different places. Explain to students that just as in the nitrogen cycle, atmospheric nitrogen can change into a different form that plants can use. Even though the structure of the nitrogen changes (nitrogen gas to nitrite and nitrate), it is still nitrogen. Have them return all blocks to the bag and turn them in. This activity should take no more than 6 or 7 minutes.