Why is Density Considered a Property of a Particular Kind of Material?
Ask the students to think of examples of properties of materials (such as color, hardness, texture, odor, break-ability, boiling point, melting point), as opposed to properties of objects (such as size and shape). Generate a list of examples on the board. Ask, “Does it make sense that density is a property of a certain kind of material? Why or why not?” Step 2: Does Cutting an Object in Half Affect its Density? Students may be aware that the size and shape of an object does not affect its density from the activity in Lesson 3. However, many students are still unclear on this point. As a reinforcement activity, have the students work in small groups. Give each group a long cylinder of Styrofoam. Ask each group to think about what would happen if you only had half of the cylinder. Would the density change or not? Make sure that students first calculate the density of the entire cylinder. Explore Outcomes Step 3: Testing Predictions Have each group discuss their predictions and how they w
