1. Iron has the atomic number 26.
2. Its chemical symbol is Fe. ‘Fe’ is an abbreviation of ‘ferrum’ – the Latin word for iron.
3. Iron’s melting point is 1535.0 °C (1808.15 °K) and boiling point is 2750.0 °C (3023.15 °K).
4. Iron is one of the 3 magnetic elements (the others are cobalt and nickel).
5. Iron is extracted from rocks and minerals called iron ores. There are several types of iron ore – haematite (Fe2O3), magnetite (Fe3O4), goethite (FeO(OH)), limonite (FeO(OH).n(H2O)), and siderite (FeCO3).
6. Iron ore, coke and limestone are heated in a blast furnace to produce pig iron.
7. Pig iron (Cast iron) contains around 5% carbon and is used for manhole covers on roads and pavements. It’s more resistant to corrosion (rust) than pure iron, but is more brittle.
8. Wrought iron is pure iron and is malleable.
9. Almost all the iron extracted from iron ore (about 98% of it) is used to make the alloy – steel: a mixture of iron and carbon (between 0.1% and 1.5%). Mild steel is contains less than 0.25% carbon and is used for construction of bridges, buildings and vehicles. Whereas, high carbon steel contains 0.5% carbon and is used for making tools.
10. Steel does react easily with oxygen in the air and rusts. Coating the steel, for example, in paint can prevent rusting. Other elements can be added to the alloy though for other desired properties. Manganese steel contains about 84% iron, 1% carbon and 15% manganese making it very hard. Stainless steel contains 80% iron, 1% carbon, 15% chromium and 4% nickel. The chromium gives it a high resistance to corrosion and stainless steel is often used to make cutlery and cookware. Titanium steel contains up to 2% titanium and varying amounts of other metals such as vanadium, nickel and chromium. Used in aircraft and armour plating, titanium steel is very hard.
11. Iron is the catalyst in the Haber process for the manufacture of ammonia from nitrogen and hydrogen gas.
N2 (g) + 3H2 (g) <—Fe—> 2NH3 (g)
12. In human physiology, iron is an essential mineral and an important component of the haemoglobin in our blood that transports oxygen to all parts of the body.
13. The average man has a total of around 3.8 g of iron in their body and the average woman about 2.3 g.
14. Iron is the fourth most abundant element in the Earth crust, comprising some 5% by mass.
15. Pure iron is highly lustrous (shiny) and is soft and white.
16. Iron is the most abundant element in the core of stellar red giants (such as Aldebaron or Arcturus) and the dense metal cores of planets such as Earth.
17. Whilst iron meteorites are more rarely witnessed falling to Earth than stony meteorites, their iron-nickel composition makes them more resistant to ablation, weathering and are easier to spot on the ground resulting in the fact that some 90% of the total mass of meteorite finds are of iron meteorites.
18. The red colour of the planet Mars is from the iron-oxide (rusty) surface of loose rock and dust.
19. Iron-56 or 56Fe (with 30 neutrons and 26 protons) is the most stable atomic nucleus of all elements and accounts for almost 92% of all naturally occurring iron isotopes.
20. It is impossible to perform fission or fusion on 56Fe and still liberate energy.