Magnesium is a chemical element wi seembol Mg an atomic nummer 12. It is a shiny gray solit which bears a close pheesical resemblance tae the ither five elements in the seicont column (Group 2, or alkaline yird metals) o the periodic cairt: thay each hae the same electron confeeguration in thair ooter electron shell producin a seemilar crystal structur.
Magnesium is the nint maist abundant element in the universe.[6][7] It is produced in muckle, agein starns frae the sequential addeetion o three helium nuclei tae a caurbon nucleus. Whan sic starns explode as supernovas, muckle o the magnesium is expelled intae the interstellar medium whaur it mey recycle intae new starn seestems. Magnesium is the aicht maist abundant element in the Yird's crust[8] an the fowerth maist common element in the Yird (efter airn, oxygen an silicon), makkin up 13% o the planet's mass an a muckle fraction o the planet's mantle. It is the third maist abundant element dissolved in seawater, efter sodium an chlorine.[9]
Magnesium occurs naiturally anly in combination wi ither elements, whaur it invariably has a +2 oxidation state. The free element (metal) can be produced artifeecially, an is heichly reactive (tho in the atmosphere, it is suin coatit in a thin layer o oxide that pairtly inhibits reactivity — see passivation). The free metal birns wi a chairactereestic brilliant-white licht. The metal is nou obteened mainly bi electrolysis o magnesium sauts obteened frae brack, an is uised primarily as a component in alumeenium-magnesium alloys, whiles cried magnalium or magnelium. Magnesium is less dense nor alumeenium, an the alloy is prized for its combination o lichtness an strenth.
Magnesium is the eleivent maist abundant element bi mass in the human bouk an is essential tae aw cells an some 300 enzymes.[10] Magnesium ions interact wi polyphosphate compoonds sic as ATP, DNA, an RNA. Hunders o enzymes require magnesium ions tae function. Magnesium compoonds are uised medicinally as common laxatives, antacids (e.g., milk o magnes), an tae stabilise abnormal nerve excitation or bluid veshel spasm in sic condeetions as eclampsia.[10]
