Ice, water and steam
Chemistry · Early Years · The School
Watching ice melt
Put an ice cube on a plate and watch it. It starts hard and cold. It ends up as a puddle. Nothing was added. Nothing was taken away. The warmth of the room did it. Now put a second cube somewhere cold. Compare the two. Which one melts first?
Water disappearing
Leave a saucer of water out for two days. Some of it goes. It has not vanished. It has gone into the air. It is too small to see. That is why washing dries on a line. Warm windy days dry washing fastest. Ask yourself why that is.
Still the same water
Ice, water and steam look completely different. But they are all the same stuff. It is just warmer or colder. Freeze the puddle again and you get your ice cube back. Nothing new was made.
Put an ice cube in a saucer. Draw round it. Come back in an hour. There is a puddle. It is the same water in a different form. Now put the saucer in the freezer. Come back later. It is ice again. And it is about the same amount. Nothing was added at any point. Nothing was taken away. If it had turned into something NEW, freezing it would not have brought the ice back.
Where the puddle goes
Water that dries has not disappeared. It has not turned into something new. It has become water vapour. That is water spread so thinly through the air that you cannot see it. You can catch it coming back. Breathe on a cold window. A mist appears. That is the water in your breath turning back into a liquid on the cold glass. It is the same journey run backwards. It is also why a cold drink gets wet on the outside on a hot day. That water came out of the air. It did not come through the glass.