What does the coefficient of thermal expansion indicate about materials?

The coefficient of thermal expansion represents the degree to which a material expands or contracts in response to temperature changes. Essentially, it quantifies how much a material's dimensions will change with a change in temperature.

For example, when a material is heated, its molecules gain energy and move apart from each other, leading to an increase in size—this is thermal expansion. Conversely, when the temperature decreases, the molecular motion slows down, and the material shrinks. The coefficient provides a numerical value that expresses this relationship; thus, it is crucial for applications where materials undergo temperature fluctuations, allowing for predictions about stability and structural integrity.

This understanding is important in engineering, construction, and various material applications to prevent issues related to thermal stress and ensuring compatibility between different materials used in conjunction.