How can the ocean be colder than 0 degrees C, the temperature at which water freezes? As it turns out, the concentration of the particles (in this case, the ions from the salt) in ocean water lowers the temperature at which the saltwater will freeze. Students will learn how ocean water freezes at a lower temperature than freshwater by
Students will use marshmallows to simulate toxins in the environment. Concentrations of these toxins will be modeled and calculated as they bioaccumulate up the food chain. Methylmercury and POPs are substances that bioaccumulate in the Arctic food chain. OASIS scientists studied these in Barrow, Alaska. (See Ocean Atmosphere Sea Ice and Snow (OASIS) Project at www.polartrec.com)
In this lesson, students learn about what archaeologists do and then practice implementing these skills with "real artifacts".
Objective
Students will:
* be able to define an artifact and an archaeologist.
* use evidence to support their decisions about the origin and use of an unknown item.