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الاثنين، 6 أبريل 2015

Iron

· Iron is a chemical element and metal. Its chemical symbol is Fe and its atomic number is 26.

· When iron and oxygen react in the presence of water or moisture, rust (iron oxide) is formed. You might have noticed your bike chain (or other parts) rusting from time to time (especially if you haven’t been taking care of it). Another word for rusting is corrosion, which describes the disintegration of materials such as iron and steel.

· Because iron oxidizes so easily, it is rarely found in a pure metal form on the Earth’s surface. It is instead removed from ores (rocks containing important minerals and elements).

· Iron is the 4th most common element in the Earth’s crust, making up around 5% of the total (usually found as iron oxide in minerals like hematite).

· The Earth’s core is thought to be made up of an iron and nickel alloy.

· Gas giant plants such as Saturn and Jupiter have cores that are rich in iron.

· Iron is the 6th most common element found in the Universe.

· Steel is a well known and commonly used alloy made from iron and a small amount of carbon (or sometimes other elements). The amount of carbon is small (usually between 0.2% and 2.0%) but it makes a huge difference to the strength.

· Steel can be around 1000 times stronger than iron in its pure form.

· The Eiffel Tower in Paris, France is made from puddle iron. Puddle iron is a form of wrought iron, an iron alloy with a very low level of carbon content. Wrought iron was used commonly throughout western history but is no longer produced in large amounts due to the availability of steel.

· The early wrought iron used in human history actually came from meteors!

· Cast iron is a type of iron that contains carbon, silicon and small amount of manganese. It was used in earlier times to build structures like cast iron bridges. Like wrought iron however, most of its uses have been replaced by steel.

· The Iron Age was a prehistoric time when useful tools and weapons were first made from iron and steel. The dates this occurred in various parts of the world varies, with historians suggesting around 12th century BC in ancient Greece and 6th century BC in Northern Europe.

· In 2006, China was the world’s largest producer of iron, making up around 33% of the world’s total production.

· Iron is relatively cheap to produce and has a large number of different uses.

· Machines, vehicles and building structures are commonly built from iron (usually in the form of steel).

· To prevent iron and steel suffering from rust damage, they can be painted, coated with plastic, galvanized (coated with zinc) or by other methods that keep out water and oxygen.

· Iron in the human body has a number of important functions including carrying oxygen to the body in the form of hemoglobin. Iron deficiency can be quite common (especially among women), with a number of possible symptoms including fatigue and weakness.

· Iron rich foods include red meat, fish, tofu, beans and chickpeas.

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Nickel

· Nickel is a chemical element with the symbol Ni and an atomic number of 28.

· In Germany during medieval times, a red mineral was found that looked like copper ore (rock). When miners couldn't extract any copper from it, they blamed a mischievous sprite of German mythology, Nickel. They decided to call this ore Kupfernickel, with the German word for copper being Kupfer.

· In 1751, Baron Axel Fredrik Cronstedt discovered nickel while trying to extract copper from the ore kupfernickel. He named the white metal substance nickel after the spirit that had given its name to the ore.

· Unintentional use of nickel has taken place since ancient times around 3500BC.

· Based on writings the alloy cupronickel is believed to have been used by the Chinese from 1400BC and exported to Britain in the 17th century.

· Nickel is a transition metal that is hard and ductile. It is a silvery-white shiny metal with a slight golden tinge.

· Nickel has a melting point of 2,651 °F (1,455 °C) and a boiling point of 5,275.4 °F (2,913 °C).

· Along with iron, cobalt and gadolinium, nickel is one of just 4 elements that are magnetic at or near room temperature.

· Major nickel deposit sites have been found in the Sudbury region of Canada(possibly of meteoric origin), New Caledonia, Russia, South Africa, Philippines,Indonesia, and Australia.

· Most uses of nickel are as an alloy metal, namely in nickel steels, brasses, bronzes and nickel cast irons. The metal is often alloyed with copper, chromium, aluminium, lead, cobalt, silver, and gold.

· Nickel was commonly used in the making of coins, however, due to the metal being a skin allergen for some people, and the fact that today cheaper metals are available the element is no longer widely used in coinage.

· People can have allergic reactions to nickel through skin contact. Traditionally, nickel has been used to make jewelry such as earrings. Nickel allergies affecting pierced ears often result in itchy, red skin, therefore many earrings are now made nickel-free.

· Nickel is also used in many other products such as magnets, rechargeable batteries, electric guitar strings, microphone capsules, and as a green tint in glass.

· Nickel is quite rare in the Earth's crust. It is 100 times more likely to be found in the Earth's core, where it is the second most abundant element behind iron.

· Nickel is one of the elements used to make stainless steel partly due to its corrosion resistant properties.

· In the U.S, a five cent coin is called a "nickel" despite being 75% copper and only 25% nickel.

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Silver

· Silver is a chemical element. Its chemical symbol is Ag and atomic number is 47.

· Silver is a soft, shiny metal that is a good conductor of electricity.

· Silver is precious metal that has been used for many years to make fine pieces of jewelry, coins, utensils and various pieces of art.

· In modern times silver is also used in dentistry, electronics, photography, mirrors and in a number of industrial applications that make use of its unique properties.

· You may have heard of the term sterling silver, this is the name given to an alloy (combination of metals) that is at least 92.5% silver by weight. The other 7.5% is made up of other metals, usually copper.

· Silver is found naturally by itself, as an alloy with gold or in an ore (a rock containing various metals and elements). Silver is often found in copper and lead ores.

· The price of silver has fluctuated dramatically over the last century, climbing as demand increases but dropping when large silver deposits are found.

· As of November 2009, gold was valued at around 65 times the value of silver by mass.

· The word silver is one of the few words in the English language that is nearly impossible to rhyme. Words such as orange, purple, breadth, wolf, depth, angst, gulf, ninth and twelfth are also difficult or impossible to rhyme. While there are some words that do actually rhyme with these examples they are usually very rare or hardly used in the modern English language.

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Uranium

· Uranium is a chemical element, its symbol is U and its atomic number is 92.

· Refined uranium is a silvery-white weakly radioactive metal.

· Uranium is hard, malleable, ductile, and a poor electrical conductor. The metal has a very high density, around 70% denser than lead, yet less dense than gold.

· There are three naturally occurring uranium isotopes. Uranium-238 is the most stable of these and makes up over 99%, uranium-235 makes up 0.72% of natural uranium and uranium-234 just 0.005%.

· German chemist Martin Heinrich Klaproth is credited with discovering uranium in 1789. He named the new element after the recently discovered planet Uranus.

· In 1841, Eugène-Melchior Péligot became the first person to isolate uranium and in 1896 Henri Becquerel discovered it had radioactive properties.

· Uranium has a melting point of 2,075 °F (1,135 °C) and a boiling point of 7,468 °F (4,131 °C).

· Uranium has been in use as far back as ancient Rome and during the Middle Ages when its orange-red to lemon-yellow shades were used as coloring agents in ceramic glazes and glass.

· Fissile isotopes of uranium have the ability to cause a nuclear chain reaction making the metal important for generating heat in nuclear power reactors and producing fissile material for nuclear weapons.

· Uranium-235 is the most important uranium isotope for the creation of nuclear reactors and weapons because it is the only naturally occurring isotope that is fissile (meaning it can be split into 2 or 3 fission fragments by thermal neutrons).

· One kilogram of 235U can theoretically produce 20 terajoules of energy, equivalent to the energy produced from 1500 tonnes of coal.

· The first atomic bomb used in World War II, dropped on Hiroshima, Japan, in 1945, contained a uranium core. Today nuclear bombs are usually made from other materials such as plutonium.

· The military uses uranium when making special ammunition. It helps make bullets and larger projectiles hard and dense enough to punch through armor.

· Over 33% of the world's uranium is mined in Kazakhstan. Other uranium mining countries include Canada, Australia, Namibia, Niger, and Russia.

· Marie Curie's discovery of radium in uranium ore meant uranium mining increased so radium could be extracted to make glow-in-the-dark paints. It takes 3 tonnes of uranium to get 1 gram of radium, leaving massive amounts of uranium waste material which was sent for use in the glazing and tiling industry.

· In addition to being weakly radioactive, uranium is also deemed a toxic metal and over exposure can affect the normal functioning of our vital organs.

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Copper

· Copper is a chemical element with the symbol Cu and an atomic number of 29.

· The word copper and its symbol Cu come from the Latin word for Cyprus "Cuprum", where the Ancient Romans mined much of their copper.

· Pure copper is red-orange in color. When it is exposed to air it darkens to a brown color and if exposed to air and water, it becomes a blue-green color called verdigris.

· The only two metals used by humans before copper were gold and meteoric iron. Copper is believed to have been in use since ancient times over 10,000 years ago.

· Small amounts of copper can be found in a natural state while the metal is also found in minerals such as cuprite, malachite, azurite, chalcopyrite and bornite.

· Copper is an essential nutrient to all living organisms. Copper deficiency in the human body is as big an health issue as iron deficiency.

· Foods rich in copper include oysters, beef, nuts, cocoa, black pepper, lobster, sunflower seeds, green olives, avocados, and wheat.

· Due to its versatility and durability, copper is referred to as "man's eternal metal".

· Copper has a melting point of 1,984.28 °F (1,084.6 °C) and a boiling point of 4,643.6 °F (2,562 °C).

· Numerous important copper alloys have been produced over human history. Brass is a mixture of copper and zinc, bronze is an alloy of copper and tin. While cupronickel is a combination of copper and nickel.

· 60% of copper is used in electrical wiring, 20% is used in roofing and household plumbing, while 15% is used in the making of industrial machinery.

· Copper is used in the making of coins for a number of countries. Coins in the U.S contain a solid copper core and layer of copper-nickel alloy.

· Copper is also found in TVs, radios, washers, dryers and some cookware.

· Over 81,000 kgs (179,000 lbs) of copper was used to build The Statue of Liberty.

· Copper is a natural antibacterial. To prevent the spread of bacteria, brass doorknobs and handrails are often used in public buildings.

· Because bacteria will not grow on it, copper has been used for centuries to line parts of ships so that barnacles and mussels do not stick to the boats.

· Nearly 80% of all the copper we have ever produced is still in use today due to the fact that copper is 100% recyclable and retains 95% of its original value.

· Copper is a plentiful natural resource on Earth. At the current rate of extraction there is enough copper in the top kilometer of the Earths crust to meet demand for 5 million years.

· A mine in Sweden called "The Great Copper Mountain" operated from the 10th century to 1992. It produced two thirds of Europe's copper requirements in the 17th century.

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