Which term describes the expansion of materials when their temperature increases?

The selected term, which describes the expansion of materials as their temperature increases, is thermal expansion. This phenomenon occurs because as the kinetic energy of the molecules within a material increases with temperature, the molecules move more vigorously and tend to occupy a larger volume. This results in the overall expansion of the material.

Understanding thermal expansion is critical in various engineering applications, where the effects of heat on materials must be considered to prevent structural damage or failure. For example, engineers must account for the expansion of train tracks or bridges in order to design safe and effective structures.

The other terms do not describe this specific phenomenon. Latent heat refers to the energy absorbed or released during a phase change of a substance, such as from solid to liquid or liquid to gas, without a change in temperature. Contraction is the opposite of expansion; it describes the decrease in size of materials when their temperature decreases. Thermal energy refers to the total kinetic energy of particles in a substance, but does not specifically denote expansion or contraction of materials based on temperature changes.