Field Museum Resources

Lesson: Conservation of Mass

Field Museum Extensions Author: Marcus McKinley, Fenwick High School

a. Related Exhibitions. 1. Traveling the Pacific. The biogeochemical cycles of earth are examples of the conservation of mass. Although materials change form, or seem to disappear in solution or appear out of nowhere, the total mass of each element on Earth does not change (disregarding radioactivity). The Traveling the Pacific exhibition shows magma bubbling up from the Earth’s interior to form the Pacific Island chains. The question to be posed to students: “Where does this mass of lava come from? Will the earth ever run out of lava?” Students can explore the exhibition to find out where the “raw materials” of the magma come from.

2. Moving Earth. Watching the movie, students should focus on the changes in exposed surface and the water levels on earth. Ask students to explain the fate of water and land during “ice age” and “hot house” periods, and ask them to relate this to the conservation of matter.

3. Evolving Planet. Have students watch the video at the end of the Permian Period gallery. The mass extinctions that have occurred over time have included loss of habitat as sea levels dropped and rose. Student discussion: Do the changes in water volume follow the law of conservation of mass? How so?

b. Harris Educational Loan Center. The Moving Earth (audio/visual). Students can watch this movie in the classroom, with the same discussion mentioned above.

c. Field Museum Science/Website Resources. 1. This “Press Room” article shows how scientists can be involved in detective work: hunting for sources or fates of a chemical, using the conservation of mass as the underlying principle of a biogeochemical cycle. Students can search the article for the different forms of carbon mentioned, talk about the many different properties of these carbon compounds, and discuss how the conservation of mass led Dr. Jenny McElwain to hypothesize that a large amount of organic material might have been burned during this period in earth’s history. http://www.fieldmuseum.org/museum_info/press/press_globalwarming.htm