6 Dry Ice Experiments To Do With Kids What is Dry Ice? It is sometimes referred to as "cardice" and is the solid form of carbon dioxide. At pressures below 5.13 atm and temperatures below −69.5 °F, CO2 changes from a solid to a gas with no intervening liquid form, through a process called sublimation. The opposite process is called deposition, where CO2 changes from the gas to solid phase (dry ice). At atmospheric pressure, sublimation/deposition occurs at−109.3 °F. 6 ways to Read More