Compounds in the +3 oxidation state are normally brown. They are oxidizing agents. They are corrosive. They are also known as ferric compounds.
There is a lot of iron in the universe because it is the end point of the nuclear reactions in large stars. It is the last element to be produced before the violent collapse of a supernova scatters the iron into space.
The metal is the main ingredient in the Earth's core. Near the surface it is found as a ferrous or ferric compound. Some meteorites contain iron in the form of rare minerals. Normally iron is found as hematite ore in the ground, much of which was made in the Great Oxygenation Event. Iron can be extracted from the ore in a blast furnace. Some iron is found as magnetite.
There are iron compounds in meat. Iron is an essential part of the hemoglobin in red blood cells.
Iron is made in large factories called "ironworks" by reducing hematite with carbon (coke). This happens in large containers called blast furnaces. The blast furnace is filled with iron ore, coke and limestone. A very hot blast of air is blown in, where it causes the coke to burn. The extreme heat makes the carbon react with iron ore, taking off the oxygen from iron oxides, and making carbon dioxide. The carbon dioxide is a gas and it leaves the mix. There is some sand in with the iron. The limestone, which is made of calcium carbonate, turns into calcium oxide and carbon dioxide when the limestone is very hot. The calcium oxide reacts with the sand to make a liquid called a slag. The slag is drained, leaving only the iron. The reaction will leave pure liquid iron in the blast furnace, where it can be shaped and hardened after cooling down. Almost all ironworks are today part of steel mills, and almost all iron is made into steel.
There are many ways to work iron. Iron can be hardened by heating a piece of metal and splashing it into cold water. It can be softened by heating it and allowing it to slowly cool. It can also be stamped by a heavy press. It can be pulled into wires. It can be rolled to make sheet metal.
In the United States, much of the iron was taken from the ground in Minnesota and then sent by ship to Indiana and Michigan where it was made into steel.
Iron is used more than any other metal. It is strong and cheap. It is used to make buildings, bridges, nails, screws, pipes, girders, and towers.
Iron is not very reactive, so it is both easy and cheap to extract from ores. It is very strong once made into steel, and is used to reinforce concrete.
There are different types of iron. Cast iron is iron made by the way described above in the article. It is hard and brittle. It is used to make things like storm drain covers, manhole covers, and engine blocks (the main part of an engine).
Steel is the most common form of iron. Steels come in several forms. Mild steel is steel with a low percentage of carbon. It is soft and easily bent, but it does not crack easily. It is used for nails and wires. Carbon steel is harder but more brittle. It is used in tools.
There are other types of steel. Stainless steel, because of the chromium content, is rust resistant, and nickel-iron alloys can remain strong at high temperatures. Other steels can be very hard, depending on the alloys added.
Wrought iron is easily shaped and used to make fences and chains.
Very pure iron is soft, and can rust (oxidize) easily. It is also fairly reactive.
Iron compounds are used for several things. Iron(II) chloride is used to make water clean. Iron(III) chloride is also used. Iron(II) sulfate is used to reduce chromates in cement. Some iron compounds are used in vitamins.
Iron deficiency is the most common nutritional deficiency in the world.
Our bodies need iron to help oxygen get to our muscles, because it is at the heart of some essential macromolecules in our bodies such as hemoglobin that cause it to work better. Many cereals have some added iron (the element "metal" iron). It is added to cereal in the form of tiny metal filings. It is even possible to see the slivers sometimes by taking an extremely strong magnet and putting it into the box. The magnet will attract these pieces of iron. Eating these small metal shavings are not harmful to our body.
Iron is most available to the body when added to amino acids – iron in this form is ten to fifteen times more digestible than than it is as an element. Iron is also found in meat, for example steak. Iron provided by diet supplements is in the form of a chemical, such as Iron(II) sulfate, which is cheap and is absorbed well. The body will not take up more iron than it needs, and it usually needs very little. The iron in red blood cells is recycled by a system which breaks down old cells. Loss of blood by injury or parasite infection may be more serious.
Iron is toxic when large amounts are taken into the body. When too many iron pills are taken, people (especially children) get sick. Also, there is a genetic disorder which damages the regulation of iron levels in the body.
Prime Minister's Questions
Prime Minister's Questions (PMQs) is a weekly event in the British Parliament. It is a chance for the Leader of the Opposition and other Members of Parliament to ask the Prime Minister questions. Until 1997 there were two short PMQs each week. Now there is one longer event, which is on a Wednesday. It can often be a loud and rowdy event with lots of MPs shouting. Once Michael Heseltine grabbed the mace and waved it around his head.
Leader of the Opposition
The Leader of the Opposition is the name given to the leader of the largest party not in government in a Westminster System of parliamentary government. The Leader of the Opposition is often seen as the alternative Prime Minister, Premier or Chief Minister. They lead an alternative government known as the Shadow Cabinet or Opposition Front Bench.
In many Commonwealth realms the full title is "Leader of Her Majesty's Loyal Opposition". This is not used in Australia. It is the duty of the Opposition party to ask questions to the Prime Minister or other ministers during Question Time.
The following is a list of Leaders of the Opposition:
Age of the Earth
The age of the Earth is estimated at a little over 4.5 billion years. Working this out was a difficult problem to solve. For most of human history, the basic facts about the planet were unknown. The problem was tackled by Earth scientists in the twentieth century.
Modern estimates are based on radioactive dating methods. The oldest minerals on Earth – small crystals of zircon from the Jack Hills of Western Australia – are at least 4.4 billion years old. Ca-Al-rich inclusions – the oldest known solid bits in meteorites formed within the solar system – are 4.567 billion years old. This gives an age for the solar system and an upper limit for the age of Earth.
The first facts about the Earth were worked out by the Ancient Greeks. A good estimate of the Earth's size was made by Eratosthenes (276 –194 ), using trigonometry. The first estimate of the Earth's age based on evidence was by Benoît de Maillet (1656–1738), a French diplomat, philosopher and naturalist. He thought the Earth must have developed by slow, natural forces. He studied geology in the field. He could see signs of erosion on land and sedimentation in the sea. He hid his ideas under the guise of a talk with an Indian philosopher, to avoid conflict with the Catholic Church. His work stayed in manuscript until after his death, when it was published after its editor had made changes which damaged it. Now there is a better modern edition based on the manuscripts. de Maillet estimated that the Earth was older than two billion years. He also recognized the true nature of fossils, and had early ideas about evolution.