What Happens to Things When You Heat Them?
Eggs
This photograph shows a batch of hen's eggs. The inside of an egg changes a lot when heated.
Irish Farmers' JournalEggs
Irish Farmers' Journal
Irish Farmers' Journal
Eggs
This photograph shows a batch of hen's eggs. The inside of an egg changes a lot when heated.
Irish Farmers' Journal
What happens when you heat different things? When you put chocolate in the microwave oven it melts. When it cools it goes hard again. Other things, like an egg, change a lot when they are heated, but do not go back to being a raw egg when they cool.
When you heat ice it changes into water. What do you get when you freeze water? Things do not always behave in the same way when they are heated and cooled. Scientists often group things together that behave similarly when they are heated (like water and chocolate).
Some Things Keep Us Warmer than Others
If you put a metal spoon in a cup of tea (CAREFUL WITH HOT WATER) do you feel the spoon getting hot? Would a wooden spoon feel the same? Can you explain?
Some things let heat pass through them easily. These are called good conductors. Others do not, and they are called insulators. Air is a very good insulator, so soft things like cotton wool, duvets, woolly coats that have air trapped in them are good insulators and keep you warm. Birds ruffle up their feathers in cold weather to trap air and keep them warm. Would you use a metal ‘jacket’ for the hot-water tank in your house to keep the heat in? (No, because metal lets heat pass heat through it).
Heat escaping
Heat escaping from house
Heat escaping
Heat escaping
Heat escaping from house
There are lots of places where the heat can escape from your house so it is important to know what materials are best to put say in the roof or around the water tank to keep the heat in.