Iron

Element 26 on the periodic table, symbol Fe, group 8, period 4.

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.

Appearance: lustrous metallic with a grayish tinge

Properties

Atomic Number: 26
Atomic Mass: 55.8452 u
Group: 8
Period: 4
Block: d-block
Category: Transition Metal
State at 25 °C: Solid
Melting Point: 1,811 K · 1,537.9 °C
Boiling Point: 3,134 K · 2,860.9 °C
Density: 7.874 g/cm³
Atomic Radius: 140 pm
Electronegativity: 1.83
Oxidation States: +2, +3
Abundance in Crust: 5.63e+4 mg/kg
Discovered: Known since antiquity
Discovered By: No individual credited

Electron Configuration

[Ar] 3d6 4s2

1s2 2s2 2p6 3s2 3p6 4s2 3d6

Ionisation Energies (kJ/mol)

1. 762.5
2. 1,561.9
3. 2,957
4. 5,290
5. 7,240
6. 9,560
7. 12,060
8. 14,580

Elements near Iron

Elements in the same group share the number of outer electrons and behave in similar ways. Elements in the same period share a shell, so they change steadily from left to right.