Magnesium
Definition and meaning of Magnesium in chemistry.
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray solid that represents the ninth most abundant element in the universe and the eighth most abundant in the Earth's crust. It is highly valued as a lightweight structural metal and is absolutely essential for cellular function in all known living organisms.
In more detail
Positioned in group 2 of the periodic table, magnesium is a moderately hard alkaline earth metal that tarnishes slightly upon exposure to air, forming a thin protective layer of magnesium oxide. Unlike the heavier alkaline earth metals, it can be safely handled in bulk, though in powdered or thin ribbon form, it ignites easily and burns with an intensely bright white flame. The element is naturally found in large deposits of magnesite and dolomite, and is also extracted in massive quantities from seawater, where the magnesium ion is highly soluble. Chemically, it readily reacts with acids and hot water, and acts as a strong reducing agent in the production of other metals like titanium and uranium. In biological systems, a magnesium ion is situated at the exact center of every chlorophyll molecule, making it indispensable for plant photosynthesis.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Mg |
| Atomic number | 12 |
| Atomic mass | 24.305 u |
| Category | Alkaline Earth Metal |
| State at room temperature | Solid |
| Melting point | 650 °C (1202 °F) |
| Boiling point | 1091 °C (1996 °F) |
| Discovery year | 1755 |
Due to its combination of low density and good mechanical strength, magnesium alloys are widely used to manufacture lightweight components for automotive engines, aerospace structures, and premium electronic devices.
Frequently asked questions
Why is a magnesium fire so difficult to successfully extinguish?
Magnesium burns at extremely high temperatures and can react chemically with water to produce flammable hydrogen gas, and with carbon dioxide, rendering standard water and CO2 fire extinguishers completely ineffective.
Why do humans need to consume adequate amounts of magnesium?
It acts as a required cofactor for over 300 enzymatic reactions in the human body, playing critical roles in energy production, muscle and nerve function, and the synthesis of DNA and RNA.