After reading about Jack Frost we made frost and looked at pictures of frost. The air around us can hold a lot of water which is called water vapor. You can’t see it but it’s usually there. We can often see this water vapor when it condenses on windows, cars, grass and cobwebs. We call this dew. Cold surfaces generally make the water vapor condense because colder air can’t hold as much water so what it can’t hold turns into droplets on surfaces. If the surface is very cold (below the freezing point of water) the condensed water vapor freezes, this is what we see as frost. In our experiment we filled a can with crushed ice and a bit of water. This makes the water and the can sit at around the freezing point of water (zero degrees Celsius). Then we added salt to get it even colder. Salt lowers the melting point of ice but by doing so it means that the surface of the can is actually below freezing point. This makes the water vapor in the air condense and freeze on the can. We had a chance to feel the salt and some of us even tasted it!