magnesium manyeziom (#) Fr.: magnésium A metallic chemical element; symbol Mg. Atomic number 12; atomic weight 24.305; melting point about 648.8°C; boiling point about 1,090°C. The Scottish chemist Joseph Black recognized it as a separate element in 1755. In 1808, the English chemist Humphrey Davy obtained the impure metal and in 1831 the French pharmacist and chemist Antoine-Alexandre Brutus Bussy isolated the metal in the pure state. The name originally used was magnium and was later changed to magnesium, which is derived from Magnesia, a district in the northeastern region of Greece called Thessalia. |