Chatt sex shqip American virtual sex
Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen and water.
Fresh iron surfaces appear lustrous silvery-gray, but oxidize in normal air to give hydrated iron oxides, commonly known as rust.
Among its organometallic compounds is ferrocene, the first sandwich compound discovered.
Pure iron is relatively soft, but is unobtainable by smelting because it is significantly hardened and strengthened by impurities, in particular carbon, from the smelting process.
A certain proportion of carbon (between 0.002% and 2.1%) produces steel, which may be up to 1000 times harder than pure iron.
Unlike the metals that form passivating oxide layers, iron oxides occupy more volume than the metal and thus flake off, exposing fresh surfaces for corrosion.
Iron metal has been used since ancient times, although copper alloys, which have lower melting temperatures, were used even earlier in human history.
Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig iron, which has a high carbon content.
Further refinement with oxygen reduces the carbon content to the correct proportion to make steel.