MAGNESIUM
ALKALINE EARTH METAL
| Atomic number: | 12 |
| Group numbers: | 2 |
| Period: | 3 |
| Electronic configuration: | [Ne] 3s2 |
| Formal oxidation number: | +2 |
| Electronegativities: | 1.31 |
| Atomic radius / pm: | 159.9 |
| Relative atomic mass: | [24.304, 24.307] |
Magnesium was discovered by Sir Humphry Davy (GB) in 1808. The origin of the name comes from the Greek word Magnesia, a district of Thessaly. It is a lightweight, malleable, silvery-white metal that burns in air with a brilliant white flame and reacts with water as temperature elevates. It can ignite in air and it reacts violently with oxidants. Magnesium is found in large deposits in the form of magnesite, dolomite and other minerals. It is usually obtained by electrolysis of melted magnesium chloride (MgCl2) derived from brines, wells and sea water. Magnesium is used in alloys to make airplanes, missiles and other uses for light metals. It has structural properties similar to aluminium. The price of 99.8 % pure magnesium granules is 111.60 € for 1000 g.
| Density / g dm-3: | 1738 | (293 K) |
| 1585 | (m.p.) | |
| Molar volume / cm3mol-1: | 13.98 | (293 K) |
| 15.33 | (m.p.) | |
| Electrical resistivity / µΩcm: | 4.45 | (20 °C) |
| Thermal conductivity / W m-1K-1: | 156 |
| Melting point / °C: | 650 |
| Boiling point / °C: | 1090 |
| Heat of fusion / kJ mol-1: | 9.04 |
| Heat of vaporization / kJ mol-1: | 127.6 |
| Heat of atomization / kJ mol-1: | 146.499 |
| First ionization energy / kJ mol-1: | 737.76 |
| Second ionization energy / kJ mol-1: | 1450.69 |
| Third ionization energy / kJ mol-1: | 7732.75 |
| in the atmosphere / ppm: | - |
| in the Earth's crust / ppm: | 32000 |
| in the oceans / ppm: | 1300 |
| Crystal structure: | hexagonal |
| Unit-cell dimensions / pm: | a=320.94, c=521.03 |
| Space group: | P63/mmc |
| Isotope | Relative atomic mass | Mass percent (%) |
|---|---|---|
| 24Mg | 23.9850419(2) | 78.99(3) |
| 25Mg | 24.9858370(2) | 10.00(1) |
| 26Mg | 25.9825930(2) | 11.01(2) |
| Balanced half-reaction | Eo / V | |
|---|---|---|
| Mg2+ + 2e- → Mg(s) | - 2.363 | |
| Mg(OH)2(s) + 2e- → Mg(s) + 2OH- | - 2.69 | |
| MgO(s) + 2H+ + 2e- → Mg(s) + H2O | - 1.722 |
| 11 Sodium | ← | 12 Magnesium | → | 13 Aluminium |
Citing this page:
Generalic, Eni. "Magnesium." EniG. Periodic Table of the Elements. KTF-Split, 18 Jan. 2024. Web. {Date of access}. <https://www.periodni.com/mg.html>.
