Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

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Unit 13: Modern Materials and the Solid State—Crystals, Polymers, and Alloys


Any two or more forms of the same element with different arrangements of atoms in their structures. For example, dioxygen (O2) and ozone (O3) are allotropes.
A substance that contains more than one (usually metallic) element and has metallic properties, such as strength, conductivity, ductility, and malleability.
Amorphous solid
A solid whose atoms or molecules are not arranged in regular, repeating patterns.
Crystalline solid
A solid whose atoms or molecules are arranged in regular, repeating patterns in any direction throughout the solid.
A small molecule that reacts to form covalent bonds with other monomer molecules over and over again to make a polymer.
A large molecule formed by the joining together (through covalent bonds) of a large number of individual molecules with low molecular mass (known as monomers).
Unit cell
The smallest repeating unit of atoms in a crystalline solid.
X-ray crystallography
A technique for determining the structure of a crystal by passing X-ray beams through it and analyzing how the repeating units of atoms diffracts (spreads) the X-rays.

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