The particles in dry ice overcomes the force of attraction between them to change directly to gaseous state.
Explanation:
Matter exists in three states- solid, liquid and gas. When heated, solid changes to liquid and then gas. However, upon condensation, gas changes to liquid and then to solid. Some solids when heated change directly to vapour without an intermediate liquid state, such vapour will also condense to solid without going through the liquid state. Example includes: ammonium chloride, iodine crystals and sulphur. These solids undergo SUBLIMATION.
Dry ice which is also known as solid frozen carbon dioxide can undergo sublimation when subjected to -78°C. What actually happens to the particles ( molecules) of the frozen carbon dioxide is the existence of weak intermolecular forces between the molecules. Since the molecules are very weakly attracted to each other, frozen carbon dioxide molecules very readily go from the solid state to the gas state at low temperatures.
