Wikijunior:The Elements/Iron

What does it look, feel, taste, or smell like?
Iron is shiny and metallic with a gray tinge. It is solid and heavy. As it oxidizes (rusts) it becomes a distinctive reddish brown.

Iron is usually a solid, and it needs to be extremely hot to melt. In fact, it melts at one and a half thousand degrees. This temperature is even hotter than the hottest part of a candle flame! To melt it, engineers and scientists have to use a torch called a welding torch. This torch melts iron, and it can be used to stick two pieces of iron together. When iron is melted, it glows red. It is literally 'red hot'.

How was it discovered?
Iron has been known to people since ancient times. It is believed that people have been using iron for at least 5,000 years.

Where did its name come from?
The modern English word iron comes from the old English word isærn, which comes from Indo-European roots meaning "strong metal" or "holy metal". (In ancient times, anything strong was considered holy, and they used the same word.) Some linguists like the "holy metal" origin since the first iron used came from meteorites that fell from the sky so were thought to have been provided by the gods. But others suggest it comes from "strong metal" since iron is much stronger than the bronze which was used before the Iron Age.

Iron's chemical symbol, Fe, comes from "ferrum", the Latin word for iron. To this day, metals that contain iron are known as 'Ferrous' metals.

 Did You Know?
 * Iron is created in massive stars before they explode in a supernova.
 * Iron is the second-most abundant metal in the Earth's crust, behind only aluminum.
 * The ion Fe2+, inside a heme group in a molecule of hemoglobin, allows blood to carry oxygen.
 * The Earth's magnetic field is generated by the movement of molten iron in the outer core.

Where is it found?
Iron makes up about 5% of the Earth's crust and a large part of the Earth's core. Iron also comes from meteorites.

On earth Iron is found mainly inside the minerals hematite (Fe2O3) and magnetite (Fe3O4.) Removing the iron from these minerals is a reasonably long process involving many large industrial factories. During this process many other elements are used in order to remove the iron, including limestone and carbon.

What are its uses?
Iron is used in a lot of alloys such as cast iron, wrought iron, steel, and carbon steel. There are many useful things made of steel including cars, trucks, ships, trains, rails, cutlery, bridges, and all kinds of different machines. In fact, there are few machines that do not use steel. Steel beams are used to reinforce large cement structures like skyscrapers and make them stronger. Iron is an essential part of hemoglobin, which carries oxygen in red blood cells. Iron also aids with the production of chlorophyll in plants. Iron is also used in iron sulfate (FeSO4), a treatment for the blood disease anemia.

Is it dangerous?
Some types of iron are dangerous to the body in large amounts. However, the intestines do not absorb that much iron, so iron poisoning only happens if there is so much iron that the intestines are damaged, or if the iron is injected. It can also be dangerous if a large chunk of it falls on your head.