What term describes the increase in size of a substance with an increase in temperature?

The increase in size of a substance with an increase in temperature is known as thermal expansion. When a substance is heated, its particles gain energy and move more vigorously, causing them to spread apart. This results in an increase in the overall volume of the substance, whether it is a solid, liquid, or gas.

Thermal expansion is a fundamental concept in physics and engineering, particularly in applications involving temperature changes, such as the design of bridges, railways, and buildings which must accommodate this expansion to avoid structural damage.

The other terms refer to different phenomena: thermal contraction describes the decrease in size of a substance when temperatures fall, while dilation typically refers to the action of expanding or enlarging in general, which can apply to various contexts in science. Contraction specifically points to the process of decreasing in size, which is the opposite of thermal expansion.