Magnesium is a chemical element in the periodic table that has the symbol Mg and atomic number 12. The free element of magnesium is a metallic silver white that is both ductile and malleable.
It was first isolated by Sir Humphry Davey in England by passing an electric current through molten Magnesium Chloride. It is abundant in nature, its chief mineral being Magnesite which has the formula MgCO3. Elemental magnesium is a sesquioxide, with the chemical formula MgO.
Magnesium is a very light metal, two-thirds the weight of aluminium . It has one of the lowest boiling points among all metals, measured at over 600°C. Magnesium is the eighth most abundant element in nature (by mass) and the fourth most common element in the Earth’s crust (by molarity).
Most common oxidation state of magnesium is +2. The free element has the electron configuration [Ne] 3s 2, which is commonly used in chemistry to describe the oxidation state of metals.
Magnesium belongs to group IIA of the periodic table , consisting of beryllium , aluminium , and zinc .
The valency of magnesium is +2. This means that the ionized form Mg2+ has two more electrons than protons and thus carries an overall charge of minus 2e. The free element, however, is a neutral atom and does not carry any charge since it has no electrons to give up nor a positive nucleus to take them.
All elements in the group IIA have 1s 22s 2 electron shells . The maximum number of electrons that can go into this shell is eight, leaving two electrons in the so-called s-subshell. These two electrons are normally withdrawn into this subshell to form a stable octet. Magnesium has the same electron configuration in the ground state as aluminium , which has four valence electrons.
The full outer shell of magnesium is the 4s 2 3d 10 electronic configuration. It needs two electrons to complete its octet, so it uses its two s-electrons to achieve this. The result is the Mg2+ ion.
These “valence electrons” can be exchanged with other elements in a covalent bond with the same number of valence electrons, forming a chemical compound. The total number of valence electrons is often not so important as how many free valence electrons are available to form bonds.
In the case of magnesium, it has two free valence electrons. This means that it can form two bonds with other atoms, yielding a total of four bonded atoms in its compound.
So magnesium is element number 12 in the periodic table . It has two free valence electrons, which are used to bond with other atoms that have two valence electrons (commonly oxygen or nitrogen).
Mg(s) + O2(g) → MgO(s) or simply 2 Mg atoms can bond with one oxygen atom. This results in the formation of a magnesium oxide, commonly known as magnesia (or, confusingly and less correctly, as `molten` Magnesium), which is a white powder that is insoluble in water and is widely used in the chemical industry.
Magnesium fluoride (MgF2) is used to produce certain types of glasses, such as continuous cast glass, and for the production of hydrofluoric acid. Magnesium chloride (magnesite) was once a popular drying agent for soldering fluxes, but has largely been replaced by other more effective drying agents.
Magnesium is also used in the highly flammable liquid fuel called oxy-acetylene, which is widely used for small welding jobs. Other uses of magnesium include fireworks (another word for `explosives`), flares and sparklers (it burns with a brilliant white light and is very hot). Additions of small quantities of magnesium to aluminium metal significantly increases the corrosion resistance.
As a result, it is used as plate on ships, aircraft and other vehicles that are exposed to salt water or salt spray. The addition of aluminium also leads to increased strength and toughness over pure aluminium. Magnesium alloys such as the aluminium-magnesium are also used in aircraft. With their low density, but very high strength, they are favoured for use in military jets and combat helicopters.
Magnesium has a regulatory role in controlling metabolic activity and blood electrolyte levels by suppressing thyroid hormone production and calcium absorption. Magnesium ions regulate the action potential of all cells in the body.
Magnesium is an essential element in living cells of all higher plants and animals, particularly in chlorophyll , which gives plants their green color. It is also found in many other organisms, including fungi, algae, viruses and bacteria . Magnesium ions are highly biologically active, having various roles in cellular metabolism , where they participate in many biological reactions, including DNA and RNA synthesis, cell division , transport of calcium ions across membranes, protein activation (phosphorylation), muscle relaxation (contraction) and neurotransmitter release .
Magnesium is required for all enzymes that synthesize adenosine triphosphate (ATP). ATP transports chemical energy within cells for metabolism. It is also needed for several other enzymes, including those involved in the synthesis of DNA, RNA , phospholipids and proteins. Magnesium ions activate numerous enzymes, including pyruvate dehydrogenase which catalyses the first step in the metabolism of carbohydrates .
Magnesium compounds are used medicinally as common laxatives, antacids (e.g., milk of magnesia), and in a number of situations where stabilization of abnormal nerve excitation and blood vessel spasm is required (magnesium sulfate).
Magnesium ions are sour , so they are found in some industrial applications, for example magnesium oxide is used as a heat-resistant refractory material .
Magnesium is used in the production of alloys such as aluminium-magnesium or iron-magnesium alloys, which are widely used for example in aerospace engineering and automotive industry due to their low density (making them ideal for aircraft) and high strength. Magnesium compounds are also often used as a reducing agents, e.g., as an alternative to sulfuric acid for the production of titanium.
Examples include: magnesium carbonate (chalk), calcium sulfate (plaster of Paris, gypsum), and lead(II) sulfide (galena). Magnesium is also used in the making of fireworks because it produces brilliant white light when burned.
Magnesium is used in the construction industry, where it can be alloyed to make high strength structural components which are very light weight. It is also used to reduce shudders (vibrations) in buildings by supporting wall and other structural elements – one way that it does this is by damping out wind vibrations. Magnesium is also used to make fire alarms. It can be alloyed with silver , aluminium and other metals, to produce a very low weight alloy known as duraluminum .
Magnesium is found in over 60 enzymes including ATP synthase which contains more magnesium than any other element on Earth. There are examples of single gene disorders that cause disruption to one or more of these enzymes, including the extremely rare magnesium transport protein defect (MTP-1), which causes MERRF syndrome. Many other enzyme defects related to energy production have been identified in humans and animals. In addition, there are many diseases that result from magnesium deficiency , examples include hyperparathyroidism , Niemann–Pick disease , Vitamin D-dependent rickets, diabetes mellitus type 2, hyperparathyroidism , , hypersensitivity to parathyroid hormone paramyotonia congenita , familial hemiplegic migraines and hereditary hearing loss .