Testing Material Properties
Plastic, metal, wood, and stone. We encounter many different materials every day. Each object around us is made of a specific material. Why are they not all made from the same material? The answer is that every material has different properties; some are hard and others are soft, some are transparent and others are opaque. For each product that is produced, the material from which it is made determines many of its properties. This is why material testing is so important. These tests allow researchers and engineers to select the appropriate material for each product. In this lesson plan, students will do their own material testing to characterize different materials and to compare their properties with each other.
- Conduct an investigation to identify at least five different properties of a material.
- Explain, with evidence, that different materials have their own unique properties.
- Use appropriate vocabulary to describe the properties of materials.
NGSS AlignmentThis lesson helps students prepare for these Next Generation Science Standards Performance Expectations:
- 2-PS1-1. Plan and conduct an investigation to describe and classify different kinds of materials by their observable properties.
|Science & Engineering Practices||Disciplinary Core Ideas||Crosscutting Concepts|
|Science & Engineering Practices||Planning and Carrying Out Investigations.
Plan and conduct an investigation collaboratively to produce data to serve as the basis for evidence to answer a question.
Engaging in Argument from Evidence. Construct an argument with evidence to support a claim.
|Disciplinary Core Ideas||PS1.A: Structure and Properties of Matter.
Different kinds of matter exist and many of them can be either solid or liquid, depending on temperature. Matter can be described and classified by its observable properties.
Patterns in the natural and human designed world can be observed.
- Two balls of the same size, but a different material. Some possibilities are glass marbles, wooden or Syrofoam balls, bouncy balls, or sports balls. The two balls should have distinct properties (e.g. bouncy versus non-bouncy, transparent versus opaque, squishy versus non-squishy, etc.)
- Various materials to test, such as:
- Wooden popsicle stick
- Plastic sandwich bag
- Piece of Styrofoam
- Play dough or clay
- Piece of paper
- Tissue paper
- Thick rubber band
- Piece of cloth or fabric
- Metal paper clips or washers
- Aluminum foil
For each student group of 3:
- 2-3 of the above-mentioned materials; 1 of each material per group. Each group should test a different set of materials.
- Bowl or cup filled with water (the bowl should be big enough to also fit each of the selected test materials)
- Medicine dropper or pipette
- One additional coin
- Paper towels
Background Information for TeachersThis section contains a quick review for teachers of the science and concepts covered in this lesson.
We encounter hundreds of different objects every day and many of them are made from different materials. Plastic, metal, ceramics, or wood are just a few materials of which objects can be made. Why is it that every object is not made from the same material? It is because different materials have different properties. Such properties include mechanical properties like flexibility, hardness, or durability; chemical properties like corrosion resistance or pH; optical properties like color or transmittance; and thermal properties like boiling point or flammability. There are many more material properties than the ones mentioned here. You can find a more extensive list in the Additional Background section.
Testing and measuring the characteristic properties of a specific material is a significant aspect of material science (Figure 1). To characterize a specific material, it is usually subjected to a range of tests. Each of these tests usually measures a different property. For example, bending and stretching a material tells us about how flexible a material is, and shining a light onto a material tells us about its optical properties. The collective properties of a material often determine what the material can be used for. Every manufactured product needs to be made of materials that are suitable for its particular application. As there are so many different materials to choose from, testing of materials can help narrow down the choices to the most appropriate selection for a specific product. For example, an umbrella needs to be made of water-resistant materials, and glasses need to be made out of transparent materials.
Figure 1. Left: Testing the tensile strength measures the force required to break a material. Right: The three-point bend is used to determine the flexibility of a material and measures the force required to bend the material under specific loading conditions.
The development of new materials is another big research area in material science. Researchers not only try to improve existing materials to make them better, but they also create completely new materials with very specific or novel properties to push the boundaries of what conventional materials can do. Semiconductors, nanotechnology, carbon fiber, and plastic are just some of the materials that have been made by humans for very specific purposes.
In this lesson plan, students will conduct their own range of material tests, which include the assessment of mechanical, chemical, and optical properties. While testing different materials, they will realize that each material has its own characteristic properties. Based on their results, students will classify different materials according to their observed properties and discuss for what purpose different materials could be used.