Review that a solution is a mixture of one or more materials dissolved in a liquid. The solution can be weak or strong depending on how much of the material is dissolved in the liquid. If more water is added to the solution, the solution becomes more dilute. If more of the material is added, the solution becomes more concentrated. Make and display the solutions of salt water, and food coloring in water in front of the
students to discuss these ideas.
Ask the students what would happen if we continue to add water to a solution--how long will the properties of the material dissolved in the water remain? How much water can be added until we can no longer tell that there is something dissolved in the
water? Describe the investigation and help the students complete the activities.