Final answer:
Dry ice, or solid CO₂, is a chemical compound known for being a very cold solid due to its sublimation at -78°C. It is extensively used as a refrigerant, particularly useful for preservation purposes and as a low carbon solution because of its direct transition from solid to gas without a liquid phase.
Step-by-step explanation:
Dry ice (solid CO₂) is a chemical compound. It is a relatively cold solid which sublimes at atmospheric pressures, directly transitioning from the solid phase to the gas without becoming liquid. This property of dry ice makes it incredibly useful as a refrigerant to cool substances rapidly, and it is often used for the preservation of foods and medical samples. Another unique characteristic of dry ice is its ability to create a dense mist when placed in a liquid due to its vigorous sublimation, which makes for dramatic visual effects.
Dry ice is so named because it doesn't become wet as it warms; instead, it turns into carbon dioxide gas. The temperature of dry ice is approximately -78°C, which is cold enough to freeze tissue instantly and as such must be handled with care. The sublimation of dry ice to carbon dioxide gas under normal atmospheric conditions also leads to its wide use as an eco-friendly cooling agent, and a low carbon solution for applications such as heat pumps.