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What Dissolves in Water?

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

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In this activity, students will investigate what happens when six different substances (salt, sugar, flour, oil, food coloring, and regular ground coffee) are mixed with water. They will begin by predicting what will happen when each substance is mixed in water. Next, students will test each substance and record their observations, and finally determine which substances dissolved in the water.

Begin by asking students to clear their working area and remove anything that could be damaged by liquids. Have the materials managers collect supplies for each group (of four) from a central location. Explain to students that today, they will learn about an important property of water, its ability to dissolve many different substances. Remind students of the focus activity (sugar disappearing when stirred in a glass of tea or water) and the criteria they decided on for “what it means to be dissolved.”

Review the worksheet with students so that they are clear about what to do. Before beginning the investigation, it is important to give the students the opportunity to decide on how they will mix the substances. They will need to agree on how vigorously and how many times to stir each substance. Students need to understand that to have a scientifically valid test, all substances must be treated the same way. Remind students not to vary their procedure just because a substance may not seem to be dissolving. Finally, make certain that students understand they must use a clean spoon for each substance and not to mix any of the substances together. After instructions are given, each group can complete the investigation independently. This activity can be conducted step-by-step with younger students.

As you circulate through the room during the investigation, encourage students to take a closer look at each substance by using their hand lens. You might also use this opportunity to record observations for each student regarding their group participation. 


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