Mysterious M&M's
What happens when one M&M is placed in water?
In this introductory activity, students will see that when an M&M is placed in water, the sugar and color coating dissolves and spreads out in a circular pattern around the M&M. When students compare their results, they will discover that every color of M&M dissolves in a similar way. The way the sugar and color dissolve in water is a property of M&M's. This introductory activity provides a basis for students to ask questions and to learn more about dissolving, identifying and controlling variables, and designing a fair test.
Materials needed for each group
 1 M&M
 1 White plastic or foam dessert plate
 Roomtemperature water
 Crayons or colored pencils
 Bucket or large bowl
 Paper towels
Notes about the materials
Be sure you and the students wear properly fitting goggles.
Activity sheet
Download the student activity sheet, and distribute one per student when specified in the activity.
Assessment
An assessment rubric for evaluating student progress during this activity is via download on this page. For this formative assessment, check a box beside each aspect of the activity to indicate the level of student progress. Evaluate overall progress for the activity by circling either “Good”, ”Satisfactory”, or “Needs Improvement”.
Question to investigate: What happens when one M&M is placed in water?

Have students read the introductory story on Activity sheet 1.1 and describe the properties of an M&M.
Distribute an M&M to each student or group of students along with Activity sheet 1.1. As students begin to explore the characteristics of an M&M, listen to the conversations that student groups are having. Students should identify properties such as the following:
 Size, shape, color, and texture
 Different colored layers on the inside
Explain to students that their descriptions of M&M’s are all properties of M&M’s. In the story on the Student Activity sheet, the student noticed that the color came off of an M&M when it fell in the water. Ask students if they ever had their M&M’s get wet and start to lose their color. Tell students that in the Try this activity, they will see what happens to the sugar and color coating of an M&M when it is placed in a plate of water.

Have students place an M&M in a dish of water and observe.
Giving students an opportunity to observe an M&M in water will give them the context and motivation to want to find out more about how M&M colors look when they dissolve in water. From this experience, you can get them to ask questions that they can investigate. Students will conduct the following procedure and record their observations.
Procedure
 Pour enough roomtemperature water into a white plastic or foam plate so that the water is deep enough to completely cover an M&M.
 Once the water has settled, place 1 M&M in the center of the plate. Be careful to keep the water and M&M as still as possible. Observe for about 1 minute.

Have students compare their results.
Ask students what they notice about the movement of the color from their M&M.
Expected results: Each colored coating of M&M will dissolve in a circular pattern around the M&M. Students may also mention the white streaks in the water from the sugar coating. If anyone notices differences such as “the color moved over to one side more than the other,” check to see that the plate is level.
Point out to students that because the water makes the colored coating come off the M&M and mix into the water, the water is dissolving the sugar and color. Because the colored coating on M&M’s dissolves in a similar pattern each time one is placed in water, this is a characteristic property of the M&M coating.
Empty the plate of water and M&M into a bucket, bowl, or sink. Dry the plate with a paper towel.

Have students write questions they could investigate for each of the variables listed on their Student Activity sheet.
Remind students that they have tested one M&M of a certain color in a plate of water that is at roomtemperature. The number of M&M’s, the color, the type of liquid the M&M’s are placed in, and the temperature of the water are variables that can be changed to do new experiments. Tell students that they should write at least one question to investigate for each variable. Encourage students to think of other variables and questions they might want to investigate.

Compile the questions students write for each variable on chart paper.
Point out particularly wellwritten questions and identify some of the ones that can be investigated using the materials in your classroom. You may want to select one question for each variable that the entire class can investigate together. Tell students that they will have a chance to investigate some of these questions.