26Solid
Fe 55.845 Atomic mass · uTransition metals
Iron
Iron is a chemical element with symbol Fe (from Latin:ferrum) and atomic number 26. It is a metal in the first transition series. It is by mass the most common element on Earth, forming much of Earth's outer and inner core.
Discovery Ancient (5000 BC)
K2L8M14N2
Physical properties
Values for the element in its standard state.
- Density
- 7.874g/cm³
- Melting point
- 1,811K
- Boiling point
- 3,134K
- Atomic radius
- 125pm
- Bonding type
- Metallic
- Molar heat
- 25.1J/(mol·K)
Inside the atom
Electron arrangement and the energy behind its behavior.
Full electron configuration
1s, 2 electrons; 2s, 2 electrons; 2p, 6 electrons; 3s, 2 electrons; 3p, 6 electrons; 3d, 6 electrons; 4s, 2 electrons;
[Ar] represents 18 core electrons. The full view shows them explicitly.
26 electrons Orbital order preserved from source
- Electronegativity
- 1.83Pauling scale
- First ionization energy
- 763kJ/mol
- Electron affinity
- 16kJ/mol
- Van der Waals radius
- Not available
Fe IronAtomic number 26
763kJ/mol
Atomic numberGaps indicate unavailable data
About iron
- Appearance
- Lustrous metallic with a grayish tinge
- Discovery
- Ancient (5000 BC)
- Data source
- Read the reference
A missing value means it is unavailable in this reference dataset. Values can vary with measurement method and conditions.