Vacuum evaporation

Have you ever spilled water on the floor and then used a towel to wipe it up? Well, imagine doing that but with something called a vacuum.

First, we put the thing we want to evaporate (like water) in a big container. This container is connected to a pump that pulls all of the air out and creates a vacuum inside (like when you suck the air out of a bag to save space).

Next, we heat up the thing we want to evaporate (like putting the towel out in the sun to dry). This makes the water turn into a gas called vapor.

Since there is no air in the container (thanks to the vacuum), the vapor can move around freely without bumping into anything. Eventually, it will come into contact with a surface that is cooler than the vapor, causing it to turn back into a liquid (like how the water on the towel disappears into the air and then collects on your skin if you touch it).

This process of heating up a liquid to turn it into a gas and then cooling it back down to turn it back into a liquid is called vacuum evaporation. It's handy for removing water from things and is used in things like making medicine, making computer chips, and even extracting salt from ocean water.