Quick answerIron (Fe) is a transition metal with atomic number 26 and an atomic mass of 55.845 (2023), in group 8, period 4. It has been known since ancient times. It is used for steel production and construction and bridges. Its electron configuration is [Ar] 3d6 4s2.
Iron is the metal that built the modern world: bridges, railways, ships, and skyscrapers all lean on steel, which is iron with a little carbon. It is also the metal in your blood, haemoglobin uses iron to carry oxygen from your lungs to every cell. The Earth's core is mostly iron, and its movement generates the magnetic field that shields us from space radiation.
Key facts
| Symbol | Fe |
|---|---|
| Atomic number | 26 |
| Atomic mass | 55.845 (IUPAC standard atomic weight, 2023) |
| Category | transition metal |
| Group | 8 |
| Period | 4 |
| Block | d-block |
| Electron configuration | [Ar] 3d6 4s2 |
| Discovered | Known since ancient times |
| Uses | steel production, construction and bridges, vehicle manufacturing, haemoglobin in blood, tools and machinery |
Overview
Iron is the metal that built the modern world: bridges, railways, ships and skyscrapers all lean on steel, which is iron with a little carbon. It has atomic number 26, an atomic mass of 55.845, and the electron configuration [Ar] 3d6 4s2, and it sits in group 8, period 4 of the periodic table. Iron has been known since ancient times, worked first from meteorites and later smelted from ore, and no single discoverer is credited with it. It is the most used of all metals, and the fourth most abundant element in Earth's crust, mined as hematite and magnetite ores. Steel, its great alloy, is made by adding carbon and other elements, and it frames buildings, builds cars and tools, and carries trains. Iron is also the metal in your blood: haemoglobin uses iron to carry oxygen from your lungs to every cell, and a shortage causes anaemia. Deep below, Earth's core is mostly iron, and its slow movement generates the magnetic field that shields the planet from space radiation. Left in damp air, iron rusts, which is why steel is painted, galvanised or alloyed into stainless steel.
Frequently asked questions
What is iron used for?
Iron is mainly used to make steel, which frames buildings, builds bridges, cars, ships and tools. It is the most used of all metals, and its ores are hematite and magnetite. Iron is also essential in the body, where haemoglobin uses it to carry oxygen in the blood, and Earth's core is mostly iron.
What is the symbol for iron?
The chemical symbol for iron is Fe, from its Latin name ferrum, rather than from the English word iron. It has atomic number 26 and a standard atomic mass of 55.845, and it sits in group 8 and period 4. Iron has been known since ancient times, so no single person is credited with discovering it.
What is the atomic number of iron?
Iron has atomic number 26, so it is the twenty-sixth element in the periodic table. Its atom holds twenty-six protons and twenty-six electrons, and its standard atomic mass is 55.845. It is a transition metal in group 8 and period 4, with the electron configuration [Ar] 3d6 4s2, and it is the most used of all metals.
Is iron a metal?
Yes, iron is a metal, a transition metal in group 8 of the periodic table. It is grey, strong and magnetic, and it is the most used of all metals, mostly as steel. It rusts in damp air, forming a flaky orange-brown oxide, which is why steel is painted, galvanised or alloyed into stainless steel to protect it.
Why is iron important in blood?
Iron is essential in blood because haemoglobin, the red pigment in red blood cells, uses iron to pick up oxygen in the lungs and release it in the tissues. Without enough iron the body cannot make enough haemoglobin, causing anaemia, with tiredness and weakness. Red meat, beans, lentils and leafy greens are rich sources.
Quick quiz
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Keep exploring
- Periodic table — all 118 elements
- Scandium (Sc) — another transition metal, atomic number 21
- Titanium (Ti) — another transition metal, atomic number 22
- Vanadium (V) — another transition metal, atomic number 23
- Chromium (Cr) — another transition metal, atomic number 24
- Manganese (Mn) — another transition metal, atomic number 25
- Cobalt (Co) — another transition metal, atomic number 27
- Nickel (Ni) — another transition metal, atomic number 28
- Copper (Cu) — another transition metal, atomic number 29
- Zinc (Zn) — another transition metal, atomic number 30
- Yttrium (Y) — another transition metal, atomic number 39
- All transition metal elements — on the periodic table
Sources & last updated
Last updated: . Figures are shown with their year; where sources disagree, the value is left out rather than estimated.