Fe
Iron
Atomic number: 26Mass: 55.845 uCategory: Transition Metal
About Iron
Iron is the most common element by mass in the Earth and fourth most common in the Earth's crust. It is the main component of steel and has been used by humans for thousands of years. Iron is vital in biology as part of haemoglobin in red blood cells.
Properties
Period
4
Group
8
Block
D
Category
Transition Metal
Electronegativity
1.83 (Pauling)
Ionization Energy
762.5 kJ/mol
Melting Point
1811 K (1538°C)
Boiling Point
3134 K (2861°C)
Density
7.874 g/cm³
Oxidation States
+2, +3, +4, +6
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²
[Ar] 3d⁶ 4s²
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:14e⁻
Shell 4:2e⁻
Real-World Uses
Steel construction
Vehicles
Machinery
Haemoglobin in blood
Magnets
Fun Fact
The Earth's solid inner core is a ball of iron and nickel the size of the Moon, spinning inside a liquid iron outer core!