Magnesium
Definition and meaning of Magnesium in chemistry.
![Magnesium element card: symbol Mg, atomic number 12, atomic mass 24.305, electron configuration [Ne] 3s², oxidation states +2, Alkaline earth metal, group 2, period 3, solid at room temperature.](/assets/images/terms/magnesium-chemical-element.webp)
Magnesium is a chemical element with the symbol Mg and the atomic number 12. This shiny gray solid is the ninth most abundant element in the universe and the eighth most abundant in the Earth's crust. Engineers value it as a lightweight structural metal, and it remains essential for all living cells.
In more detail
Magnesium sits in group 2 of the periodic table as a moderately hard alkaline earth metal. The pure metal tarnishes slightly in air to create a thin protective layer of magnesium oxide. Unlike heavier alkaline earth metals, humans can safely handle solid pieces of bulk magnesium.
However, magnesium powder or thin ribbons ignite easily and burn with an intense white flame. You can find large natural deposits of this element in magnesite and dolomite rocks. Industrial companies also extract massive amounts of magnesium directly from ordinary seawater.
This works well because the magnesium ion dissolves very easily in salty ocean water. Chemically, solid magnesium reacts quickly when exposed to strong acids or hot water. It also acts as a strong reducing agent during the production of other metals.
A reducing agent is a substance that donates electrons to another chemical during a reaction. In biological systems, a magnesium ion sits exactly at the center of every chlorophyll molecule. This critical central position makes the metal absolutely necessary for plant photosynthesis to occur.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Mg |
| Atomic number | 12 |
| Atomic mass | 24.305 u |
| Category | Alkaline-Earth-Metal |
| Melting point | 650 °C |
| Boiling point | 1091 °C |
Magnesium features a very low density combined with surprisingly good mechanical strength. Manufacturers mix it with other metals to create strong, lightweight alloys for various industries. Automakers use these alloys to cast lighter engine parts and structural components for cars. Aerospace engineers also use them to build lightweight frames and cases for premium electronic devices.
Frequently asked questions
Why is a magnesium fire so difficult to successfully extinguish?
Magnesium burns at extremely high temperatures and reacts with water to produce flammable hydrogen gas. It also reacts with carbon dioxide, making standard fire extinguishers completely useless.
Why do humans need to consume adequate amounts of magnesium?
Magnesium acts as a required cofactor for over 300 enzymatic reactions in the human body. A cofactor is a helper molecule that enzymes need to function properly.
Related terms
Sources & references
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