Iron forms compounds in a wide range of oxidation states, −4 to +7. Iron shares many properties of other transition metals, including the other group 8 elements, ruthenium and osmium. Ĭhemically, the most common oxidation states of iron are iron(II) and iron(III). ![]() Iron is also the metal at the active site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants and animals. To maintain the necessary levels, human iron metabolism requires a minimum of iron in the diet. These two proteins play essential roles in vertebrate metabolism, respectively oxygen transport by blood and oxygen storage in muscles. The body of an adult human contains about 4 grams (0.005% body weight) of iron, mostly in hemoglobin and myoglobin. electrolytic iron) are more resistant to corrosion. Unlike the oxides of some other metals that form passivating layers, rust occupies more volume than the metal and thus flakes off, exposing more fresh surfaces for corrosion. Iron reacts readily with oxygen and water to produce brown-to-black hydrated iron oxides, commonly known as rust. Pristine and smooth pure iron surfaces are a mirror-like silvery-gray. The iron and steel industry is thus very important economically, and iron is the cheapest metal, with a price of a few dollars per kilogram or pound. In the modern world, iron alloys, such as steel, stainless steel, cast iron and special steels, are by far the most common industrial metals, due to their mechanical properties and low cost. That event is considered the transition from the Bronze Age to the Iron Age. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys-in some regions, only around 1200 BCE. It is the fourth most common element in the Earth's crust, being mainly deposited by meteorites in its metallic state, with its ores also being found there.Įxtracting usable metal from iron ores requires kilns or furnaces capable of reaching 1,500 ☌ (2,730 ☏) or higher, about 500 ☌ (932 ☏) higher than that required to smelt copper. It is, by mass, the most common element on Earth, just ahead of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is a metal that belongs to the first transition series and group 8 of the periodic table. Unfortunately, there was a slightly different system in place in Europe.Iron is a chemical element with the symbol Fe (from Latin ferrum 'iron') and atomic number 26. The first two groups are 1A and 2A, while the last six groups are 3A through 8A. The traditional system used in the United States involves the use of the letters A and B. ![]() There are two different numbering systems that are commonly used to designate groups, and you should be familiar with both. ![]() These two rows are pulled out in order to make the table itself fit more easily onto a single page.Ī group is a vertical column of the periodic table, based on the organization of the outer shell electrons. Periods 6 and 7 have 32 elements, because the two bottom rows that are separate from the rest of the table belong to those periods. Period 1 has only two elements (hydrogen and helium), while periods 2 and 3 have 8 elements. A new period begins when a new principal energy level begins filling with electrons. There are seven periods in the periodic table, with each one beginning at the far left. \) (Credit: User:Cepheus/Wikimedia Commons Source: (opens in new window) License: Public Domain)Ī period is a horizontal row of the periodic table.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |