Iron
Iron (铁, symbol Fe) is chemical element number 26, a Transition Metal in period 4, group 8 of the periodic table, with a standard atomic weight of about 55.845. Most common element on Earth by mass. Core of hemoglobin and the iron age civilization.
Properties
| Atomic number | 26 |
|---|---|
| Symbol | Fe |
| Atomic mass | 55.845 u |
| Category | Transition Metal |
| Period | 4 |
| Group | 8 |
| Electron configuration | [Ar] 3d⁶ 4s² |
| Electronegativity | 1.83 |
| Covalent radius | 132 pm |
| Density | 7.874 g/cm³ |
| Melting point | 1811 K |
| Boiling point | 3134 K |
| Discovery | Known since antiquity |
Overview
Most common element on Earth by mass. Core of hemoglobin and the iron age civilization. Iron (Fe) is a Transition Metal with atomic number 26, located in period 4, group 8. As a transition metal it commonly shows several oxidation states, forms coloured compounds, and is widely used in catalysts and alloys.
Its electron configuration is [Ar] 3d⁶ 4s², with 2 electrons in the outer shell, and an electronegativity of about 1.83 (Pauling). Around 25 °C it is usually a solid; it melts near 1811 K (1537.9 °C), boils near 3134 K (2860.9 °C), has a density around 7.874 g/cm³.
In industry and daily life it turns up in Structural / Alloys, Catalysis and Medical / Pharma. It has been known since antiquity.
Electron shells
Electrons per shell: 2 · 8 · 14 · 2
Main uses
- Structural / Alloys
- Catalysis
- Medical / Pharma
Hazard
Compounds containing Iron
No compounds in this knowledge base contain Iron yet.
Data sources
Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.