Fe
Iron is the most widely used metal and the most abundant element on Earth by mass.
Physical Properties
| Atomic Mass | 55.845 u |
| Density | 7.874 g/cm³ |
| Melting Point | 1811.0 K |
| Boiling Point | 3134.0 K |
| Appearance | Lustrous metallic with grayish tinge |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 1.83 (Pauling) |
| 1st Ionization Energy | 762.5 kJ/mol |
| Electron Affinity | 14.6 kJ/mol |
| Oxidation States | +2, +3, +4, +5, +6 |
Atomic Properties
| Electron Configuration | [Ar] 3d6 4s2 |
| Atomic Radius | 126.0 pm |
| Covalent Radius | 132.0 pm |
| Van der Waals Radius | 194.0 pm |
Discovery
| Discovered By | Known since antiquity |
| Location | Various |
| Named After | Anglo-Saxon 'iren'; symbol Fe from Latin 'ferrum' |
About Iron
Iron is a lustrous, ductile, malleable, silver-gray metal and the most used of all metals. It forms much of Earth's core. Iron has been used by humans for at least 5,000 years. Hemoglobin uses iron to transport oxygen in blood.
Uses & Applications
Steel production, construction, automobiles, machinery, tools, cast iron cookware, and dietary supplements.
Fun Fact
Iron is literally in your blood -- hemoglobin uses iron atoms to carry oxygen. The average adult body contains about 4 grams of iron.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 54 | 0.05845% | - | Yes |
| 56 | 0.91754% | - | Yes |
| 57 | 0.02119% | - | Yes |
| 58 | 0.00282% | - | Yes |
Electron Configuration
[Ar] 3d6 4s2