Sublimation - GCSE Physics Definition

Sublimation is the process where a solid changes directly into a gas without first becoming a liquid. This happens when particles in the solid gain enough energy to break away and turn into a gas, skipping the liquid stage. A common example is dry ice, which is frozen carbon dioxide. When dry ice is exposed to air, it doesn't melt into a liquid, but instead turns straight into a gas. Understanding sublimation helps in studying how different materials interact with heat and can be used in things like freeze-drying food or in the design of spacecraft.