Deposition (phase transition)

Deposition is when a gas turns directly into a solid without going through the liquid phase. Imagine that you are pretending to breathe like a dragon and you blow out warm air from your mouth. If you blow this air on a cold surface like a window, you will see that the air turns into frosty or icy patterns. This is deposition in action!

Scientists call this phenomenon deposition because it is the opposite of sublimation, which is when a solid turns directly into a gas without going through the liquid phase. Both of these phase transitions are caused by changes in temperature and pressure.

Deposition happens because the gas molecules slow down and lose energy as they come into contact with a cold surface. When they slow down enough, they stick together and form a solid. This solid can look like frost, snow, or even thin films on a surface.

Deposition is an important part of many natural processes, such as the formation of snowflakes, the growth of frost on a window, and the formation of stalactites and stalagmites in caves. Scientists also use deposition to make thin films for electronic devices, such as computer chips, by depositing a thin layer of material onto a surface.

So, the next time you blow out warm air on a cold window and see frosty patterns forming, you can impress your friends by explaining that it's deposition in action – the gas turning directly into a solid!