Iron
How is a paper clip like a skyscraper? How is blood like a car? The answer to both questions is the same. All of these things contain iron.
Iron is one of the most useful metals. Its strength makes it ideal for building things that will last. Yet it can also be easily worked and shaped. People have been using iron for a long time. Iron beads 6,000 years old have been found in Africa.
WHERE IS IRON FOUND?
Our planet contains a huge amount of iron. Scientists believe that Earth’s core is about nine-tenths iron. This giant ball of iron generates Earth’s magnetic field and makes compasses work.
We can’t get at the iron at the center of the planet. But there is plenty of iron in Earth’s outer layer, or crust. Iron is the second-most common metal in the crust after aluminum.
Iron is rarely found in a pure state. The purest natural iron comes from meteorites that have fallen from space. Meteorite iron was the first form of iron that ancient peoples used.
Iron is usually found combined with other elements in rocks. These rocks are called iron ores. They are found in many parts of the world.
HOW IS IRON USED?
Iron must be purified from its ores by smelting. In this process, rocks that contain iron are crushed and melted in a very hot furnace. Molten iron is separated out. People first discovered how to do this around 1350 bc. Iron is much harder than bronze, which was the most commonly used metal until that time. Iron made stronger tools and weapons.
Iron’s strength and abundance make it especially useful. But most of the iron we use today is in the form of steel. Today, steel is used to make automobiles and ships. It is used for tall buildings, bridges, and for making many kinds of tools.
STEEL IS MADE FROM IRON
Pure iron breaks easily. It also combines with oxygen in the air. This combination produces the flaky, reddish material we call rust. For this reason, most of the iron we use today is not pure.
Iron can be made much stronger if it is heated together with a bit of carbon. Iron and carbon combine to make steel. Nearly all the iron mined today goes into making steel. Steel can be formed into many sizes and shapes, depending on how it is used.
Small amounts of other elements can be added to steel. For example, adding chromium and nickel makes stainless steel. Stainless steel stays shiny and resists rust. It is used for many things, including pots and pans, forks, knives, and spoons. It is also used to make surgical tools and to patch broken bones.
EATING IRON
Except for some bacteria, all living things require iron to live. That’s why people are often told to add more iron to their diet. Of course, this does not mean gnawing on a chunk of metal! Certain foods contain tiny amounts of iron combined with other elements. Grains such as wheat, meat (especially liver), beans, and some green vegetables are rich in iron.
Your body uses iron to carry oxygen from your lungs to the rest of your body. The iron in hemoglobin, a substance found in blood, does that job. The iron combined with oxygen in hemoglobin also gives blood its red color.
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