Resource Type
Completion Time
About 1 period
Middle School and Up
Download, Share, and Remix
Jeanine Gelhaus
4 different densities of salt water (colored)
2 test tubes
Test tube holder
1 clear straw
Worksheet for every student
Life Science
Earth Science
Water Cycle, Weather, and Climate


Through investigation, you will determine which solution has the highest density.


To determine, through experimentation, which of a variety of solutions has the highest density.


Background: The waters of the ocean are constantly moving in many different ways. The surface of the ocean rises and falls in rhythm. These movements, in the form of waves, include the tides, tsunamis, and swells of ocean beaches. Below the surface, ocean currents contribute to the heat transport from the tropics to the poles, partially equalizing Earth's surface temperatures. As a result, ocean circulation patterns influence climate and living conditions for life both in the ocean and on land. While you can easily see surface water moving, it is sometimes difficult to recognize that the water below the surface also has motion. Deep water currents are mainly caused by differences in the density of water. The density or heaviness of the water is affected by temperature and salinity. The saltier the water, the more dense it is. Cold water is also more dense than warm water. The coldest, most dense ocean water on earth is found off the coast of Antarctica. Because of its density, the cold Antarctic water sinks to the bottom of the ocean floor and flows north through the world's oceans. At the same time, warm surface currents near the equator flow southward toward Antarctica


Follow the attached activity lab sheet. Model the tipping of the test tube on its side to minimize mixing of solutions, as well as the cleaning of the test tube between experiments to avoid contamination.


See attached activity sheet


Jeanine Gelhaus Capstone Project Fall 2013. Integrated Life and Earth Sciences in the Polar Regions.