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About Iron

Iron Bohr Model

As the major component of Earth’s core and the fourth most common element in the crust, iron is the most common element on the planet. Iron is a transition metal that has been known since ancient times, though meteoric iron was the only source of the element in metallic form until the widespread adoption of iron smelting techniques that began around 1500 BCE, a development that launched the period of history often termed the Iron Age. Producing iron metal from ore requires higher temperatures than could be achieved with the primitive furnaces used to produce bronze and pottery, and this along with the skill required to produce functional iron objects meant that iron working was a substantial technological advancement.

Though truly pure metallic iron is actually quite soft, producing the metal from ore results in the inclusion of carbon, which substantially alters the properties of the material. The earliest iron products were made from wrought iron, which generally contained less than one percent carbon. This product was tough, malleable, ductile, easily welded, and suitable for producing general purpose tools; however, it also contained many impurities, had low tensile strength, and took considerable effort to work into functional objects. Later, furnaces hot enough to melt iron were developed, allowing for the production of cast iron. The higher carbon content of cast iron made it too brittle for use in weapons or tools that would sustain impact, but it was more resistant to rust than wrought iron and could easily be cast in desired forms.

Early forms of iron working are now largely obsolete, though traditional cast iron is still used for cookware, and a related product engineered to be less brittle, ductile iron, is often used for water and sewer lines. Using iron to its full potential requires careful control of its composition, which allows for the production of alloys with a wide range of properties. Most ferrous alloys in common use are steels, meaning that they are primarily iron with a carbon composition between 0.002 and 2.1 percent, which results in a product that is neither too soft nor too brittle. Steel was produced sporadically as early as 4000 years ago, and by 500-400 BCE, cultures around the world produced the metal regularly, but the methods used were labor intensive and costly, and the metal was used only when there was no alternative--primarily for items requiring a hard, sharp edge, such as knives, razors, and swords. Methods slowly improved over the centuries, but it wasn’t until the introduction of the Bessemer process in 1855 that steel was produced cheaply and in the large quantities necessary for modern industry.

Today, literally hundreds of varieties of steels are produced for various applications. Simple carbon steel, consisting only of iron and carbon, is sufficient for many uses, from structural applications to springs and high strength wires. Addition of other elements, however, provides many advantages. Low alloy steel contains ten percent or less of elements other than iron and carbon, usually added to improve hardenability. Stainless steels contain at least eleven percent chromium, sometimes along with other elements, and are designed to resist corrosion. Many other specialty steels exist, including tool steels, which include large amounts of tungsten or cobalt and can maintain a long-lasting shape edge, and Cor-ten, a steel that weathers to a uniform rusted surface that is stable without surface treatments.

Iron is also used to produce magnets. Ferrite magnets are non-conductive magnetic ceramics made of iron oxide, and are frequently used in transformers, electromagnets, and radios. Neodymium-iron-boron magnets are the strongest permanent magnets known, and are used in motors, hard-disk drives, and magnetic fasteners. Before the development of such rare earth magnets, the strongest known magnets were alloys of iron, nickel, aluminum, and cobalt known as Alnico magnets. These are still used widely in almost any application where strong permanent magnets are needed, but increasingly neodymium magnets are used when their higher strength for a given size is a more important factor than their increased cost. Additionally, iron nanoparticles can be suspended in liquid to produce magnetic suspensions known as ferrofluids; these are used widely in ferrofluidic seals.

In addition to use in alloys and magnets, iron is commonly used in the form of compounds. Prussian blue, one of the first synthetic pigments produced, is an iron compound with a complex structure, and its brilliant color results from the presence of iron in multiple oxidation states. It is used widely in blue and black inks and paints, and produces the familiar blue of blueprints. Iron chloride is used in water treatment, as a catalyst, and to etch copper as part of the production of printed circuit boards. Iron pyrite, also known as fool’s gold, is a semiconductor that is of interest for use in photovoltaic devices, though crystal defects in the material as commonly grown have presented a challenge for researchers. Iron is also a vital trace nutrient, and is frequently used as a nutritional supplement, often in the form of iron sulfate.

Though iron silicates and carbonates are more common natural sources of the metal, all industrial sources are iron oxide ores, as the metal can be more easily extracted from these ores than more common forms. The highest quality deposits are hematite, which can be up to seventy percent irons, but some magnetite ores are also economically feasible iron sources.


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Iron and its compounds have numerous uses. It is the most commonly used metal for commercial applications due to its hardness, historical availability, and low cost. Once used on its own, it is now alloyed with carbon, nickel and other elements to produce steel and other high strength, non-corrosive, structural metals. High Purity (99.999%) Iron Oxide (Fe2O3) PowderIron is a primary colorant in glass and ceramics. High Purity (99.999%) Iron (Fe) Sputtering TargetIt is also used as a catalyst. It is the basis for low grade magnets and, because of its magnetic properties, is used in memory tape and magnetic resonance imaging (MRI). Iron is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Iron nanoparticles and nanopowders are also available. Oxides are available in powder and dense pellet form for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Iron fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Iron is also available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Iron Properties

Iron Bohr ModelIron(Fe) atomic and molecular weight, atomic number and elemental symbolIron is a Block D, Group 8, Period 4 element. The number of electrons in each of Iron's shells is 2, 8, 14, 2 and its electron configuration is [Ar] 3d6 4s2. Elemental IronThe iron atom has a radius of and its Van der Waals radius is In its elemental form, CAS 7439-89-6, Iron has a lustrous grayish metallic appearance. Iron is the fourth most common element in the Earth's crust and the most common element by mass forming the planet earth as a whole. Iron is usually found in the form of magnetite (Fe3O4), hematite (Fe2O3), goethite (FeO(OH)), limonite (FeO(OH) . n(H2O)) or siderite (FeCO3). It is rarely found in its pure metallic form since it tends to oxidize.

Symbol: Fe
Atomic Number: 26
Atomic Weight: 55.845
Element Category: transition metal
Group, Period, Block: 8, 4, d
Color: lustrous, metallic, grayish tinge/ silvery-gray
Other Names: Ferrum, Fer, Eisen, Ferro, Hierro
Melting Point: 1538 °C, 2800 °F, 1811 K
Boiling Point: 2862 °C, 5182 °F, 3134 K
Density: 7.874 g/cm3
Liquid Density @ Melting Point: 6.98 g/cm3
Density @ 20°C: 7.87 g/cm3
Density of Solid: 7874 kg·m3
Specific Heat: 0.45 kJ/kg/K
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: 8,227 °C (8,500 K) , MPa
Heat of Fusion (kJ·mol-1): 14.9
Heat of Vaporization (kJ·mol-1): 340.2
Heat of Atomization (kJ·mol-1): 413.96
Thermal Conductivity: 80.4 W·m-1·K-1
Thermal Expansion: (25 °C) 11.8 µm·m-1·K-1
Electrical Resistivity: (20 °C) 96.1 nΩ·m
Tensile Strength: 20 KPSI
Molar Heat Capacity: 25.10 J·mol-1·K-1
Young's Modulus: 211 GPa
Shear Modulus: 82 GPa
Bulk Modulus: 170 GPa
Poisson Ratio: 0.29
Mohs Hardness: 4
Vickers Hardness: 608 MPa
Brinell Hardness: 490 MPa
Speed of Sound: (r.t.) (electrolytic) 5120 m·s-1
Pauling Electronegativity: 1.83
Sanderson Electronegativity: 2.2
Allred Rochow Electronegativity: 1.64
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: 2.17
Reflectivity (%): 65
Refractive Index: N/A
Electrons: 26
Protons: 26
Neutrons: 30
Electron Configuration: [Ar] 3d6 4s2
Atomic Radius: 126 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 132±3 (low spin), 152±6 (high spin) pm
Covalent Radius (Å): 1.24
Van der Waals Radius: 200 pm
Oxidation States: 6, 5, 4, 3, 2, 1, -1, -2 (amphoteric oxide)
Phase: Solid
Crystal Structure: body-centered cubic/ face-centered cubic
Magnetic Ordering: ferromagnetic
Electron Affinity (kJ·mol-1) 14.564
1st Ionization Energy: 762.47 kJ·mol-1
2nd Ionization Energy: 1561.90 kJ·mol-1
3rd Ionization Energy: 2957.49 kJ·mol-1
CAS Number: 7439-89-6
EC Number: 231-096-4
MDL Number: MFCD00010999
Beilstein Number: N/A
SMILES Identifier: [Fe]
InChI Identifier: InChI=1S/Fe
PubChem CID: 23925
ChemSpider ID: 22368
Earth - Total: 32.07%
Mercury - Total: 64.47%
Venus - Total: 31.17%
Earth - Seawater (Oceans), ppb by weight: 3
Earth - Seawater (Oceans), ppb by atoms: 0.33
Earth -  Crust (Crustal Rocks), ppb by weight: 63000000
Earth -  Crust (Crustal Rocks), ppb by atoms: 23000000
Sun - Total, ppb by weight: 1000000
Sun - Total, ppb by atoms: 30000
Stream, ppb by weight: 670
Stream, ppb by atoms: 12
Meterorite (Carbonaceous), ppb by weight: 2.2E+08
Meterorite (Carbonaceous), ppb by atoms: 77000000
Typical Human Body, ppb by weight: 60000
Typical Human Body, ppb by atom: 6700
Universe, ppb by weight: 1100000
Universe, ppb by atom: 20000
Discovered By: N/A
Discovery Date: before 5000 BC
First Isolation: N/A

Health, Safety & Transportation Information for Iron

Iron is not toxic; however, safety data for Iron and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) Iron.

Safety Data
Signal Word N/A
Hazard Statements N/A
Hazard Codes N/A
Risk Codes N/A
Safety Precautions N/A
RTECS Number N/A
Transport Information N/A
WGK Germany nwg
Globally Harmonized System of
Classification and Labelling (GHS)
Review and Print SDS for Iron Metal


Date Created: 05/15/2015
Date Revised: 05/15/2015


Product Name: Iron Metal

Product Number: All applicable American Elements product codes, e.g. FE-M-02, FE-M-03, FE-M-04, FE-M-05

CAS #: 7439-89-6

Relevant identified uses of the substance: Scientific research and development

Supplier details:
American Elements
1093 Broxton Ave. Suite 2000
Los Angeles, CA 90024
Tel: +1 310-208-0551
Fax: +1 310-208-0351

Emergency telephone number:
Domestic, North America +1 800-424-9300
International +1 703-527-3887


Classification of the substance or mixture
Classification according to Regulation (EC) No 1272/2008
The substance is not classified as hazardous to health or the environment according to the CLP regulation.
Classification according to Directive 67/548/EEC or Directive 1999/45/EC
Not applicable
Information concerning particular hazards for human and environment:
No information known.
Hazards not otherwise classified
No information known.
Label elements
Labelling according to Regulation (EC) No 1272/2008
Not applicable
Hazard pictograms
Not applicable
Signal word
Not applicable
Hazard statements
Not applicable
WHMIS classification
Not controlled
Classification system
HMIS ratings (scale 0-4)
(Hazardous Materials Identification System)

Health (acute effects) = 0
Flammability = 0
Physical Hazard = 0
Other hazards
Results of PBT and vPvB assessment
Not applicable.
Not applicable.


Chemical characterization: Substances
CAS# Description:
7439-89-6 Iron
Identification number(s):
EC number:


Description of first aid measures
General information
No special measures required.
After inhalation
Supply fresh air. If required, provide artificial respiration. Keep patient warm.
Seek immediate medical advice.
Seek medical treatment in case of complaints.
After skin contact
Immediately wash with water and soap and rinse thoroughly.
Generally the product does not irritate the skin.
Seek immediate medical advice.
After eye contact
Rinse opened eye for several minutes under running water. Then consult a doctor.
Rinse opened eye for several minutes under running water. If symptoms persist, consult a doctor.
After swallowing
Seek medical treatment.
Information for doctor
Most important symptoms and effects, both acute and delayed
No further relevant information available.
Indication of any immediate medical attention and special treatment needed
No further relevant information available.


Extinguishing media
Suitable extinguishing agents
Special powder for metal fires. Do not use water.
For safety reasons unsuitable extinguishing agents
Special hazards arising from the substance or mixture
If this product is involved in a fire, the following can be released:
Iron oxides
Advice for firefighters
Protective equipment:
No special measures required.
Wear self-contained respirator.
Wear fully protective impervious suit.


Personal precautions, protective equipment and emergency procedures
Wear protective equipment. Keep unprotected persons away.
Not required.
Ensure adequate ventilation
Environmental precautions:
Do not allow material to be released to the environment without proper governmental permits.
Do not allow product to reach sewage system or any water course.
Do not allow to penetrate the ground/soil.
Methods and material for containment and cleaning up:
Pick up mechanically.
Prevention of secondary hazards:
No special measures required.
Reference to other sections
See Section 7 for information on safe handling
See Section 8 for information on personal protection equipment.
See Section 13 for disposal information.


Precautions for safe handling
Keep container tightly sealed.
Store in cool, dry place in tightly closed containers.
Information about protection against explosions and fires:
No special measures required.
Conditions for safe storage, including any incompatibilities
Requirements to be met by storerooms and receptacles:
No special requirements.
Information about storage in one common storage facility:
Not required.
Further information about storage conditions:
Keep container tightly sealed.
Store in cool, dry conditions in well sealed containers.
Specific end use(s)
No further relevant information available.


Additional information about design of technical systems:
Properly operating chemical fume hood designed for hazardous chemicals and having an average face velocity of at least 100 feet per minute.
Control parameters
Components with limit values that require monitoring at the workplace:
7439-89-6 Iron (100.0%)
EV (Canada) Long-term value: 1* 5** mg/m³
as iron;*salts, wate
r-soluble;**welding fume
TLV (Canada) Long-term value: 5 mg/m³
Additional information:
No data
Exposure controls
Personal protective equipment
General protective and hygienic measures
The usual precautionary measures for handling chemicals should be followed.
Keep away from foodstuffs, beverages and feed.
Remove all soiled and contaminated clothing immediately.
Wash hands before breaks and at the end of work.
Maintain an ergonomically appropriate working environment.
Breathing equipment:
Use suitable respirator when high concentrations are present.
Not required.
Protection of hands:
Impervious gloves
Not required.
Penetration time of glove material (in minutes)
Not determined
Eye protection:
Safety glasses
Body protection:
Protective work clothing


Information on basic physical and chemical properties
General Information
Form: Solid in various forms
Color: Grey
Odor: Not determined
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 1538 °C (2800 °F)
Boiling point/Boiling range: 2740 °C (4964 °F)
Sublimation temperature / start: Not determined
Flammability (solid, gaseous)
Not determined.
Ignition temperature: Not determined
Decomposition temperature: Not determined
Auto igniting: Not determined.
Danger of explosion: Not determined.
Explosion limits:
Lower: Not determined
Upper: Not determined
Vapor pressure: Not applicable.
Density at 20 °C (68 °F): 7.87 g/cm³ (65.675 lbs/ga
Bulk density at 20 °C (68 °F): 2900 kg/m³
Relative density
Not determined.
Vapor density
Not applicable.
Evaporation rate
Not applicable.
Solubility in / Miscibility with Water: Insoluble
Partition coefficient (n-octanol/water): Not determined.
dynamic: Not applicable.
kinematic: Not applicable.
Other information
No further relevant information available.


No information known.
Chemical stability
Stable under recommended storage conditions.
Thermal decomposition / conditions to be avoided:
Decomposition will not occur if used and stored according to specifications.
Possibility of hazardous reactions
No dangerous reactions known
Conditions to avoid
No further relevant information available.
Incompatible materials:
No information known.
Hazardous decomposition products:
Iron oxides


Information on toxicological effects
Acute toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains acute toxicity
data for this substance.
LD/LC50 values that are relevant for classification:
Oral LD50 30000 mg/kg (rat)
Skin irritation or corrosion:
Powder: irritant effect
Eye irritation or corrosion:
Powder: irritant effect
No sensitizing effects known.
Germ cell mutagenicity:
No effects known.
The Registry of Toxic Effects of Chemical Substances (RTECS) contains tumorigenic and/or carcinogenic and/or neoplastic data for this substance.
No classification data on carcinogenic properties of this material is available from the EPA, IARC, NTP, OSHA or ACGIH.
Reproductive toxicity:
No effects known.
Specific target organ system toxicity - repeated exposure:
No effects known.
Specific target organ system toxicity - single exposure:
No effects known.
Aspiration hazard:
No effects known.
Subacute to chronic toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains multiple dose toxicity
data for this substance.
Additional toxicological information:
To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.
Carcinogenic categories
OSHA-Ca (Occupational Safety & Health Administration)
Substance is not listed.


Aquatic toxicity:
No further relevant information available.
Persistence and degradability
No further relevant information available.
Bioaccumulative potential
No further relevant information available.
Mobility in soil
No further relevant information available.
Additional ecological information:
General notes:
Do not allow material to be released to the environment without proper governmental permits.
Avoid transfer into the environment.
Results of PBT and vPvB assessment
Not applicable.
Not applicable.
Other adverse effects
No further relevant information available.


Waste treatment methods
Consult state, local or national regulations to ensure proper disposal.
Uncleaned packagings:
Disposal must be made according to official regulations.


Not applicable
UN proper shipping name
Not applicable
Transport hazard class(es)
Not applicable
Packing group
Not applicable
Environmental hazards:
Not applicable.
Special precautions for user
Not applicable.
Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code
Not applicable.
Transport/Additional information:
Marine Pollutant (DOT):


Safety, health and environmental regulations/legislation specific for the substance or mixture
National regulations
All components of this product are listed in the U.S. Environmental Protection Agency Toxic Substances Control Act Chemical substance Inventory.
All components of this product are listed on the Canadian Domestic Substances List (DSL).
SARA Section 313 (specific toxic chemical listings)
Substance is not listed.
California Proposition 65
Prop 65 - Chemicals known to cause cancer
Substance is not listed.
Prop 65 - Developmental toxicity
Substance is not listed.
Prop 65 - Developmental toxicity, female
Substance is not listed.
Prop 65 - Developmental toxicity, male
Substance is not listed.
Information about limitation of use:
For use only by technically qualified individuals.
Other regulations, limitations and prohibitive regulations
Substance of Very High Concern (SVHC) according to the REACH Regulations (EC) No. 1907/2006.
Substance is not listed.
The conditions of restrictions according to Article 67 and Annex XVII of the Regulation (EC) No 1907/2006 (REACH) for the manufacturing, placing on the market and use must be observed.
Substance is not listed.
Annex XIV of the REACH Regulations (requiring Authorisation for use)
Substance is not listed.
REACH - Pre-registered substances
Substance is listed.
Chemical safety assessment:
A Chemical Safety Assessment has not been carried out.


Safety Data Sheet according to Regulation (EC) No. 1907/2006 (REACH). The above information is believed to be correct but does not purport to be all inclusive and shall be used only as a guide. The information in this document is based on the present state of our knowledge and is applicable to the product with regard to appropriate safety precautions. It does not represent any guarantee of the properties of the product. American Elements shall not be held liable for any damage resulting from handling or from contact with the above product. See reverse side of invoice or packing slip for additional terms and conditions of sale. COPYRIGHT 1997-2016 AMERICAN ELEMENTS. LICENSED GRANTED TO MAKE UNLIMITED PAPER COPIES FOR INTERNAL USE ONLY.

Iron Isotopes

Iron has 4 stable isotopes: 54Fe (5.845%), 56Fe (91.754%)57, Fe (2.119%) and 58Fe (0.282%).

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
45Fe 45.01458(24)# 4.9(15) ms [3.8(+20-8) ms] ß+ to 45Mn; ß+ + 2p to 43Mn 3/2+# N/A 321.33 -
46Fe 46.00081(38)# 9(4) ms [12(+4-3) ms] ß+ to 46Mn; ß+ + p to 45Mn 0+ N/A 342.45 -
47Fe 46.99289(28)# 21.8(7) ms ß+ to 47Mn; ß+ + p to 46Mn 7/2-# N/A 357.98 -
48Fe 47.98050(8)# 44(7) ms ß+ to 48Mn; ß+ + p to 47Mn 0+ N/A 377.24 -
49Fe 48.97361(16)# 70(3) ms ß+ + p to 48Mn; ß+ to 49Mn (7/2-) N/A 391.84 -
50Fe 49.96299(6) 155(11) ms ß+ to 50Mn; ß+ + p to 49Mn 0+ N/A 410.16 -
51Fe 50.956820(16) 305(5) ms ß+ to 51Mn 5/2- N/A 423.83 -
52Fe 51.948114(7) 8.275(8) h EC to 52Mn 0+ N/A 439.36 -
53Fe 52.9453079(19) 8.51(2) min EC to 53Mn 7/2- N/A 450.24 -
54Fe 53.9396105(7) STABLE - 0+ N/A 463.91 5.845
55Fe 54.9382934(7) 2.737(11) y EC to 55Mn 3/2- N/A 472.92 -
56Fe 55.9349375(7) STABLE - 0+ N/A 484.72 91.754
57Fe 56.9353940(7) STABLE - 1/2- 0.09062294 491.87 2.119
58Fe 57.9332756(8) STABLE - 0+ N/A 501.81 0.282
59Fe 58.9348755(8) 44.495(9) d ß- to 59Co 3/2- 0.29 508.96 -
60Fe 59.934072(4) 1.5(3)E+6 y ß- to 60Co 0+ N/A 517.04 -
61Fe 60.936745(21) 5.98(6) min ß- to 61Co 3/2-,5/2- N/A 523.25 -
62Fe 61.936767(16) 68(2) s ß- to 62Co 0+ N/A 531.33 -
63Fe 62.94037(18) 6.1(6) s ß- to 63Co (5/2)- N/A 535.68 -
64Fe 63.9412(3) 2.0(2) s ß- to 64Co 0+ N/A 542.83 -
65Fe 64.94538(26) 1.3(3) s ß- to 65Co 1/2-# N/A 547.18 -
66Fe 65.94678(32) 440(40) ms ß- to 66Co; ß- + n to 65Co 0+ N/A 554.33 -
67Fe 66.95095(45) 394(9) ms ß- to 67Co; ß- + n to 66Co 1/2-# N/A 558.68 -
68Fe 67.95370(75) 187(6) ms ß- to 68Co; ß- + n to 67Co 0+ N/A 563.97 -
69Fe 68.95878(54)# 109(9) ms ß- to 69Co; ß- + n to 68Co 1/2-# N/A 567.39 -
70Fe 69.96146(64)# 94(17) ms Unknown 0+ N/A 572.67 -
71Fe 70.96672(86)# 30# ms [>300 ns] Unknown 7/2+# N/A 576.09 -
72Fe 71.96962(86)# 10# ms [>300 ns] Unknown 0+ N/A 581.37 -