What is sublimation in terms of phase changes?

Sublimation refers to the phase change in which a solid transitions directly into a gas without first becoming a liquid. This process occurs under specific conditions, typically at low pressure or when the temperature is elevated, allowing molecules within the solid to gain enough energy to break free from their fixed positions and disperse as gas.

An example of sublimation is dry ice (solid carbon dioxide) which, upon exposure to room temperature, transitions directly into carbon dioxide gas. This unique phase change is of interest in various scientific and practical applications, including freeze-drying and certain chemical processes. Understanding sublimation is vital in fields such as chemistry and materials science, highlighting the fundamental concepts of phase changes and energy transfer.