Magnesium is a shiny gray solid and the ninth most abundant element in the universe. It has similar physical properties to other Group 2 elements due to their shared outer electron configuration. Magnesium is synthesized in large, aging stars and expelled into the interstellar medium by supernovas, then recycled into new star systems, making it the eighth most common element in the Earth's crust and fourth most common overall.

1. Magnesiumisachemicalelementwith
symbolMg andatomicnumber12.It isa shinygray solidwhichbearsaclosephysicalresemblancetothe
otherfiveelementsinthesecondcolumn(Group2,or alkalineearthmetals)oftheperiodictable:theyeach
havethe sameelectronconfigurationintheirouterelectronshellproducingasimilarcrystalstructure.
Magnesiumistheninthmostabundantelementintheuniverse. Itissynthesizedinlarge,agingstarsfrom
thesequentialadditionofthreeheliumnucleitoacarbonnucleus.Whensuchastarexplodesasa
supernova,muchofitsmagnesiumisexpelledintothe interstellarmedium,whereitcanberecycledintonew
starsystems.Consequently,magnesiumistheeight mostabundantelementintheEarth'scrustandthe
fourthmostcommonelementintheEarth(belowiron,oxygenandsilicon),makingup13% oftheplanet's
massanda largefractionofthe planet'smantle.Itisthethirdmostabundantelementdissolvedinseawater,
aftersodiumandchlorine.