Iron
Transition Metal
Iron (Fe) is a chemical element with atomic number 26, classified as a transition metal. At room temperature it is a solid. It has been known since ancient times.
Properties
- Atomic number
- 26
- Atomic mass
- 55.845 u
- Category
- Transition Metal
- Group
- 8
- Period
- 4
- Block
- d-block
- Electron configuration
- [Ar] 3d⁶ 4s²
- Phase at STP
- Solid
- Density
- 7.874 g/cm³
- Melting point
- 1811 K (1537.8 °C)
- Boiling point
- 3134 K (2860.8 °C)
- Electronegativity
- 1.83
- Atomic radius
- 156 pm
- Ionization energy
- 7.902 eV
- Discovery
- Known since ancient times
Common uses
Steel, magnets, construction, hemoglobin in blood
Did you know?
Most common element on Earth by mass and essential for life.
Compounds you can make with iron
Iron appears in 3 compounds in our periodic table sandbox. Each one is a real substance with its true chemical formula — combine the right elements in the right ratio below to discover it.
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Fe2O3
Iron(III) Oxide (Rust)
The reddish-brown crust that forms when iron reacts with oxygen and water.
-
FeS
Iron(II) Sulfide
A dark compound; "fool’s gold" (pyrite) is a related iron sulfide.
-
FeCl3
Iron(III) Chloride
A dark salt used to treat wastewater and to etch copper circuit boards.