Fire Extinguisher Sublimation

We release carbon dioxide from a fire extinguisher against a dark cloth to see what happens. The expanding gas cools as it leaves the extinguisher, forming a visible dry ice solid on the cloth. As it warms, the carbon dioxide vanishes and the solid turns to gas without going through a liquid stage, demonstrating sublimation.

Chemistry - Atoms And Bonding - Learning Points.
Most solids melt to liquids and then evaporate to gases.
Most gases condense to liquids and then freeze to solids.
Carbon dioxide is an exception because the solid sublimes directly to the gas.

A Twig Experiment Film.
Let students experience real experiments in lab conditions anywhere, from setup, method all the way through to analysis and real-world application.