10.1 Thermal Expansion
Thermal expansion is the change in length, area, or volume of a substance when it is heated. As the temperature rises, the particles within a substance gain more kinetic energy. This causes them to move faster and spread out, leading to expansion of the material.
Conversely, when a substance is cooled, its particles lose energy and move closer together, causing the material to contract. This phenomenon is known as thermal contraction.