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How Can We Find Out What Is in Water?

Author(s): Nancy P. Moreno, PhD, Barbara Z. Tharp, MS, and Judith Dresden, MS.

Mystery Liquid

Small amounts of many different substances can be dissolved in water at the same time. Many of these substances are not visible or distinguishable when mixed together in water. In this activity, students will use a simple separation technique to detect the presence of several different food dyes in water.

Ask students if they are able to identify all the food colors used to create the liquid in the photo. Now, show students the mystery liquid. Ask them, Can you tell what is in this liquid? 

Explain that each student is going to become a detective and investigate the contents of the mystery liquid.

Funded by the following grant(s)

National Institute of Environmental Health Sciences, NIH

National Institute of Environmental Health Sciences, NIH

The Environment as a Context for Opportunities in Schools
Grant Numbers: 5R25ES010698, R25ES06932

Houston Endowment Inc.

Houston Endowment Inc.

Foundations for the Future: Capitalizing on Technology to Promote Equity, Access and Quality in Elementary Science Education