Discovery date : 1755
Discovered by: Joseph Black
Origin of the name: The name is derived from Magnesia, a district of Eastern Thessaly in Greece.
Allotropes :
~>MAGNESIUM is a chemical element with symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column (group 2, or alkaline earth metals) of the periodic table: all group 2 elements have the same electron configuration in the outer electron shell and a similar crystal structure.
| FACT BOX | |||
| Group | 2 | Melting point | 650°C, 1202°F, 923 K |
| Period | 3 | Boiling point | 1090°C, 1994°F, 1363 K |
| Block | s | Density (g cm−3) | 1.74 |
| Atomic number | 12 | Relative atomic mass | 24.305 |
| State at 20°C | Solid | Key isotopes | 24Mg |
| Electron configuration | [Ne] 3s2 | CAS number | 7439-95-4 |
| ChemSpider ID | 4575328 | ChemSpider is a free chemical structure database | |
The first person to recognise that magnesium was an element was Joseph Black at Edinburgh in 1755. He distinguished magnesia (magnesium oxide, MgO) from lime (calcium oxide, CaO) although both were produced by heating similar kinds of carbonate rocks, magnesite and limestone respectively. Another magnesium mineral called meerschaum (magnesium silicate) was reported by Thomas Henry in 1789, who said that it was much used in Turkey to make pipes for smoking tobacco.
An impure form of metallic magnesium was first produced in 1792 by Anton Rupprecht who heated magnesia with charcoal. A pure, but tiny, amount of the metal was isolated in 1808 by Humphry Davy by the electrolysis of magnesium oxide. However, it was the French scientist, Antoine-Alexandre-Brutus Bussy who made a sizeable amount of the metal in 1831 by reacting magnesium chloride with potassium, and he then studied its properties.