For example, aspirin (see page 26) was first discovered in tree bark, but we do not get it from trees anymore. This means scientists can make them in the lab. Chopping down trees for wood destroys forest habitats where animals live. This breaks up the seabed, and can kill sea creatures. For example, we dig under the seabed for oil. Some of them are being used up.Ĭollecting materials can damage the planet, too. But Earth does not have an endless supply of these materials. We get materials such as rock, oil, wood, metal, and precious stones from nature. Aluminum is removed from the heated clay.
Here, a conveyor belt takes a special clay called bauxite from a mine in Australia to a nearby smelter.
Power stations burn coal, oil, or gas to produce electricity. Fuel made from oil powers cars and planes. Some of the particles then split open other atoms. In nuclear fission, an atom is broken apart. It can also be used to make very powerful nuclear weapons. Unfortunately, this invention has brought problems. Nuclear power comes from nuclear fission. If an atom is split open, it releases energy. It works well for building houses but would be useless for making pants.Ĭan you think of other things that work better when they are made of particular materials? Which materials could you make a good coffee cup out of? Which materials would not make a good cup-and why? Here's a list of materials to consider: wood, cork, cotton fabric, chocolate, china, steel, plastic, sponge, stone.
So it is made of plastic, wood, or rubber. For example, a screwdriver has to be strong and hard, so it has a steel tip. Properties decide how a material is used. What color is it? Is it see-through? Does it float? Does it burn easily? Does it feel warm or cold to touch? Does it conduct (carry) electricity? The Right Material Other properties include how strong, stretchy, or flexible (bendy) a material is. Air is a mixture of oxygen, nitrogen, and other gases.ĭifferent materials have different features and ways of behaving. Mixture: A material made of different substances mixed together. Matter: The stuff from which everything is made.Įlement: A material that is the same throughout, such as gold or silver.Ĭompound: A substance made of molecules, each of which is made up of two or more different types of atoms. Several words are used to describe matter and materials. Modern materials such as plastics and carbon fiber are used to make sports gear, like this snowboard and helmet. These axe heads and arrowheads were carved about 9,000 years ago, during the Stone Age.
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