The process of converting a solid directly into gas is called sublimation. This physical change occurs without passing through a liquid state. Sublimation happens under specific conditions of temperature and pressure, where certain substances, like dry ice (solid carbon dioxide) or iodine, transition from solid to gas. This process is utilized in various applications, including freeze-drying food, where water is removed from food by sublimation, preserving texture and flavor. Understanding sublimation is essential in both scientific contexts and everyday items, such as air fresheners or certain types of refrigerants.