Iron Definition and 517 Threads

Iron () is a chemical element with symbol Fe (from Latin: ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust.
In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching 1,500 °C (2,730 °F) or higher, about 500 °C (900 °F) higher than that required to smelt copper. Humans started to master that process in Eurasia by about 2000 BCE, and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron Age. In the modern world, iron alloys, such as steel, stainless steel, cast iron and special steels are by far the most common industrial metals, because of their mechanical properties and low cost.
Pristine and smooth pure iron surfaces are mirror-like silvery-gray. However, iron reacts readily with oxygen and water to give brown to black hydrated iron oxides, commonly known as rust. Unlike the oxides of some other metals, that form passivating layers, rust occupies more volume than the metal and thus flakes off, exposing fresh surfaces for corrosion. Although iron readily reacts, high purity iron, called electrolytic iron, has better corrosion resistance.
The body of an adult human contains about 4 grams (0.005% body weight) of iron, mostly in hemoglobin and myoglobin. These two proteins play essential roles in vertebrate metabolism, respectively oxygen transport by blood and oxygen storage in muscles. To maintain the necessary levels, human iron metabolism requires a minimum of iron in the diet. 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.Chemically, the most common oxidation states of iron are iron(II) and iron(III). Iron shares many properties of other transition metals, including the other group 8 elements, ruthenium and osmium. Iron forms compounds in a wide range of oxidation states, −2 to +7. Iron also forms many coordination compounds; some of them, such as ferrocene, ferrioxalate, and Prussian blue, have substantial industrial, medical, or research applications.

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  1. S

    An accelerated iron Ion moving through a mass spectrometer's field

    Homework Statement A sample of two different iron ions, Fe2+ and Fe3+, are accelerated by the same potential and then sent through the uniform magnetic field of a mass spectrometer. a) Which ion moves faster after being accelerated? b) Which ion follows the path with the largest radius...
  2. J

    Products and energy from Iron 56 fission

    I know the iron-56 nucleus is not a good fission candidate, and that more energy is required to split iron-56 than what is required to split it. But theoretically, if one were to split iron-56, what would be the products and what would be the energy obtained per unit mass? Would there be...
  3. C

    B field inside solenoid as a result of iron rod

    Homework Statement Consider a solenoid with a time varying current and with a coil of wire placed around it. Suppose there is a soft iron rod inside the solenoid. My question is: What happens to the (induced) current in the coil of wire as a result? Homework Equations Faraday, magnetic...
  4. J

    Iron Man 3D Impressions: What's Your Review?

    I saw Iron Man 3D last night, and I wanted to know from those who have watched it or will watch it, what do you think of it? The plot, characters, and production. In my opinion, it was good, but Avengers had better special effects. Iron man however had a better plot.
  5. 2

    How to Calculate Windings for a 1 T Solenoid Electromagnet with Iron Core

    How do i calculate the amound of windings I need to make an solonoid electro magnet with around 1 T.. I checked with google, and there seesm to be a lot of different formulaes which confusses me alot..
  6. F

    Is the Iron Man suit realistic in present times?

    Is it possible to create the iron man suit in present times with all the technology involved in it? I was doing some research about the mini. arc reactor, Jet boots, and helmet and what I found was with the helmet we would need to program something like Watson to guide anyone inside of the...
  7. W

    What Makes Iron Ferromagnetic?

    is this basic fact understood?
  8. M

    Dislocations in FCC and BCC iron due to C interstitials

    I was just wondering why is it that the strengthening effect of interstitial carbon is different in FCC and BCC iron alloys. I can't figure this one out on my own so I thought I'd come to the place where the smart people hang out. Any opinions?
  9. mishima

    Dissolving iron in HCl, unknown product

    My class needed some iron (iii) chloride to determine the purity of some aspirin they synthesized, so I thought I might try making some. I left a strip of iron in concentrated HCl for a few nights under the fume hood. I was expecting a liquid with iron (ii) chloride to result, which would then...
  10. C

    Finding unit cell dimensions of iron or copper

    Homework Statement The research notes from an x-ray diffraction experiment were damaged and information was lost. The wavelength of the x-rays used in the experiment, and measurements of the three smallest Bragg angles (θ) from the sample were all that remained: they were 0.71Å, 10.1°, 14.4°...
  11. J

    How to Clean a Cast Iron Fry Pan with Thick Calcium Deposits?

    How would be the easiest way to clean a cast iron fry pan that has been heated with water in it that had calcium in the water as now it has calcuim deposited 1/8" thick? John
  12. W

    Melting and recasting pure iron bars?

    Hello Wizards! I need to produce specially pure iron shapes for a research project. As you may know, pure iron is hard to find. Small pure iron bars are the easiest. Is it possible to melt and cast these small pure iron bars into other shapes, without the iron losing its...
  13. B

    Can Fine Iron Powder Be Compressed into a Solid Puck Without Heat or Binders?

    I was just curious if it would be possible to compress fine iron powder into a solid puck without applying any heat or binding chemicals, etc. I'm guessing it would take several tonnes of force? Particle size of powder: about 30 microns
  14. D

    Magnetic field outside a wire coiled on an iron cyl.

    If we consider the common electromagnet that is made by passing current through a wire coiled around an iron core, I wonder what effect produces more magnetic field: 1. The field produced outside the solenoid due to the current in the wire 2. For this effect I don't insist that the object is...
  15. Z

    Thermal effect of heat input on an iron rod - magnetostriction

    If an iron rod, inside two coils, incurs current going through the coils in the same direction, then the rod will increase in length and then it will begin to reduce in length. This is due to the magnetostrictive properties of the iron. When the currents oppose each other, so as to cancel...
  16. A

    Force between a bar magnet and iron

    I'm an inventor and I have an idea involving magnets. Unfortunately, I'm having a hard time trying to interpret magnetic equations. Please forgive me if I sound like a noob.. I'm new to magnetism. Lets say you have a bar magnet with a field B, oriented perpendicular to a wooden interface...
  17. P

    What causes brittleness in cast iron?

    I want to know, what exactly gives brittleness to cast iron. Have read many articles on it but people beat around bush and don't answer the question what exactly makes it very brittle. Thanks
  18. R

    Finding Sound Velocity in Iron: Examining Dispersion Curves

    I want to define (and find the sound velocity i iron). can i read it through the dispersion curves of iron? I am trying to see it through the group propagation velocity, vg = dw/dk, i. e the slope of the dispersion relation w(k). am i on the right track? thanks
  19. deep838

    The translational force on a piece of iron in a magnetic field

    Ok so if there be a piece of iron in a uniform magnetc field B, what will be the force on the iron? You can assume any variable you want, but i want to find the magnetic force that causes the iron pieces to move towards the magnet in terms of any variables, like it corss-sectional area, length...
  20. Q

    My Iron from the Earth: A Childhood Memory

    When I was a child, I picked a iron from the earth. It looks a iron, it has a thin layer rust outside. but the shape looks like a stone. it is about 26mm long. I erase a little rust by knife. then the position will not get rusty afterwards in the room even many years.
  21. B

    Does the Dri Buddi Really Dry Clothes and Iron them Out?

    There is this new product on the market called the Dri Buddi Clothes Dryer that claims to use less electricity than a regular tumble dryer, flattens out the clothes with jets of hot air coming from its blower, does not damage or shrink clothing, does not have filters that need cleaning, is...
  22. V

    George Russ, rogue oceanologist, dumped 100 tons of Iron Sulfate into the ocean

    http://www.nytimes.com/2012/10/19/science/earth/iron-dumping-experiment-in-pacific-alarms-marine-experts.html Last fall. His intention is the stimulate the growth of phytoplankton, thus absorbing CO2. He also did so in violation of several UN charters (or whatever their rules are...
  23. F

    Energy required to demagnetize Iron.

    How would i go about calculating the AC current and overall energy required to demagnetize an Iron plate that has been magnetized by a permanent magnet?
  24. T

    What's Going On When Iron Electrodes Are Electrolyzed in Sodium Hydroxide?

    I've got a question that is bugging me If I have a concentrated sodium hydroxide solution and electrolyze it with iron electrodes, some of the possible reactions at the positive electrode are 2H2O -> O2 + 4H++4e-. Eo = -1.23 V 4OH- -> O2 + 2H2O + 4e-. Eo = -0.40 V Fe -> Fe2+ + 2e-. Eo = 0.44...
  25. H

    Calculate electromagnetic force on iron object

    Hello, I need to calculate/estimate the force between a solenoid electromagnet and a piece of iron on a certain distance from the magnets airgap, preferable in a simple way under ideal conditions rather than a very exact calculation. I have found the following formula at a couple of places...
  26. C

    Can Cast Iron Pistons Seal Without Seals?

    as far as i understand, piston have cast iron seals because of the properties of cast iron, which make it a sealing material. but i was wondering, if the cylinder and piston are both made of cast iron and closely fitted together, could we avoid using seals all together? friction doesn't depend...
  27. M

    Iron and plumbum (lead) on a balance in air and water

    On the flat bottom of an aquarium is an old fashioned balance. On one scale of the balance is a piece of plumbum, on the other side is a piece of iron. The scales are exactly in balance. Now we let the aquarium fill slowly with water, until the entire balance is under water. What happens now...
  28. F

    Magnetic field of iron core solenoid

    When we calculate magnetic field of iron core solenoid, should we multiply "relative permeability" or "effective permeability"? I thought that we should use relative permeability, but wiki(http://en.wikipedia.org/wiki/Solenoid) says that we should use effective permeability. I'm so...
  29. Astronuc

    News RIP Lee Dorman, bass player for Iron Butterfly

    Lee Dorman died Friday morning. http://news.yahoo.com/iron-butterfly-bassist-lee-dorman-dies-age-70-005219358.html Orange County sheriff's spokeswoman Gail Krause says that Dorman may have been enroute to a doctor when he died. Iron Butterfly's iconic album In-A-Gadda-Da-Vida was one...
  30. I

    Discerning the Elasticity Modulus of Brittle Cast Iron from Test Data

    Here goes try number two, the forum deleted my last post. :cry: First time poster, so hopefully I'm following the rules, I do apologise if I'm not. I have a problem with my lab report, I would be very grateful if anyone could help. Thanks. Homework Statement I'm writing a tensile test lab...
  31. Z

    What Makes Iron Effective at Blocking Radiation Compared to Lead?

    Does anyone know how Iron compares to lead as a medium to block / absorb radiation? Do you know what wavelengths or spectrum iron is most effective against?
  32. K

    Electromagnetic induction with two coils and an iron heart

    Homework Statement Two coils are place on an iron heart, like in the picture. The top Coil is connected to a galvanometer, the second could be connected to a power source. Homework Equations Will an electric current flow through the top coil when: a) connecting and then...
  33. O

    Does Temperature Equalize Between Iron and Wood in Thermal Equilibrium?

    If I put an iron of 350K and a wood of 300K in contact, then put them in a container so that they are adiabatic. The question : after a very long time will they become thermal equilibrium? same temperature? My guess : they should be same. But they have different specific heat capacities. If the...
  34. J

    Why exactly Is Iron cooler than it's environment at 20°c?

    I've been doing classical physics and specific heat so I started wondering why some materials cool and/or heat faster, I figured it probably had something to do with how close together the atoms were in the material or such... than i started thinking why are matters like Iron always so cold when...
  35. M

    Need help with iron solenoid/core for an electromagnet?

    i'm making an electromagnet with a battery, some copper wire, and a iron solenoid/core. For the core I'm using is a magnetic spoon, i was just wondering, will it work? here's a picture, http://img706.imageshack.us/img706/9348/spoont.jpg , I'm not done wrapping the wire basically it's...
  36. N

    Formation of elements heavier than iron

    I know that in the process of fusion in Stars, the hydrogen fuses into helium and so on until Iron is formed. The fusion stops after the formation of Iron and the graviatational force wins to take over the star evolution. Then how do we account for the elements which are havier than Iron?
  37. C

    Why Does Earth Have an Iron Core?

    Why is Earth's nucleus mostly made from iron?
  38. D

    US Source for Lithium Iron batteries

    Does anyone out there know of a US based source or distributor for high capacity lithium batteries? 100Ah, 200Ah? 3 - 3.2 volts Everything I am finding is China, and the shipping is just outrageous. Thanks, pud
  39. S

    How Are Elements Beyond Iron Created in Stars?

    A friend wrote this in an exchange we had about iron and its role in the process of fusion. I question the last sentence. Is it right, and what is the "coating"? The creation of the element iron via fusion "is the final peal of a star's natural life" (if the star is massive enough to even get...
  40. P

    What Would Be the Mass of an Iron-Dense Empire State Building?

    If an object the size of the empire statbuilding had iron density,what would be ... the mass of it? The estimated volume of the empire state building is 37 million cubic feet,how could I calculate the mass of this solid object if it had a density of Iron(which would be 7870 kg/m³)?
  41. S

    Electromagnetism with an iron core

    Homework Statement When we have an iron core in a solenoid, the iron core will become magnetised. But if I were to put a piece of iron in front of the iron and solenoid the piece of iron will come out like in a door chime. But as it comes out, will the magnetic field be stretched and elongated...
  42. G

    Does Iron Lose Mass When Exposed to Water and Oxygen?

    When iron corrodes in water, it loses electrons to oxygen and becomes iron ions. The oxygen retrieved the free electrons and along with water molecules formed hydroxide ions. Eventually, the iron ions and hydroxide ions react to form iron hydroxide. So based on this, would the iron loses mass...
  43. N

    How to Scale Up Production of Iron (III) Oxide?

    Good day to you all. A few days ago i attempted produced Iron oxide (III). Here is what i have done: What i have done 1: I put water in a plastic container " 2: I added salt (3 tablespoons) to the water " 3: I applied electricity...
  44. S

    Electromagnetic induction on iron core question

    Homework Statement An iron core with a solenoid coiled around it is in a circuit with a switch and a dc current supply. In front of it, there is a iron ring tied to the ceiling such that it faces the solenoid without touching the circuit. When the switch is turned on what is observed and...
  45. J

    Calculating thickness of a cast iron cylinder carrying pressure of 30Nmm^2

    1. Homework Statement A cast-iron cylinder of 300mm bore carries a pressure of 30 Newtons per square millimetre; what should be its thickness for a unit working stress of 25 Newtons per square millimetre? 2. Homework Equations ó1 = pd/2t t=pd/2tó1 3. The Attempt at...
  46. J

    Finding thickness of a cast iron cylinder

    Homework Statement A cast-iron cylinder of 300mm bore carries a pressure of 30 Newtons per square millimetre; what should be its thickness for a unit working stress of 25 Newtons per square millimetre?Homework Equations ó1 = pd/2t t=pd/2tó1The Attempt at a Solution t=pd/2tó1 t= 30*300/2*25...
  47. F

    U-shaped iron core with I-shaped iron core vs without

    I have two coils standing next to each other. One is connected to a power supply and the other one is connected to a lamp. When I put an I-shaped iron core through both coils the lamp shines brighter than without the iron core. The same thing happens when I use a U-shaped iron core. When I...
  48. S

    Find the mass of iron used in the experiment.

    Homework Statement "A student reacts an unknown mass of iron (Fe) in an excess of sulfuric acid (H2SO4). The balanced equation is: 2 Fe(s) + 3sH2SO4(aq) → Fe2(SO4)3(aq) + 3 H2(g) She records the following data: 23.0°C...
  49. K

    Electromagnet construction and off-axis field calculation with iron core

    Hi, I'm wondering if anyone has any sources for off-axis point calculation for multiple current carrying loops that contain a soft iron core. I have been using this resource so far and I can figure out how to include multiple loops. How would I approach these calculations with an iron core...
  50. R

    Does natural iron have a denser nucleous then lab made iron?

    I've heard Iron has the most condensed nucleous out of all the elements, and I asume it is due to the enormous amount of pressure in a stars core just before the end of its life. My question is if we made iron in a lab, would its nucleous be just as condensed as natural iron or would it be...
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