Distinction should be made by identifying and dividing materials into four classifications, based on the following definitions:
- Metal—-any of a category of electropositive elements that usually have a shiny surface, are generally good conductors of heat and electricity, and can be melted or fused, hammered into thin sheets, or drawn into wires. Typical metals form salts with nonmetals, basic oxides with oxygen, and alloys with one another.
- Ceramic—any of various hard, brittle, heat-resistant, and corrosion-resistant materials made by shaping and then firing a nonmetallic mineral, such as clay, at a high temperature
- Polymer—any of numerous natural and synthetic compounds of usually high molecular weight consisting of up to millions of repeated linked units, each a relatively light and simple molecule
- Composite—a complex material, such as wood or fiberglass, in which two or more distinct, structurally complementary substances, especially metals, ceramics, glasses, and polymers, combine to produce structural or functional properties not present in any individual component
Process/Skill Questions:
- What characteristics that make a material easily identifiable as a metal, ceramic, or plastic?
- What properties are unique to each material classification?
- Where are metals and nonmetals found on the periodic table?
- Why can wood be considered a composite or polymer material?