Ah magnesium, Mg if you will or if you are in a hurry.
It's a chemical element with an atomic number of 12. A shiny and gray solid, it bears a close physical resemblance to the other five elements in the second column (group 2, or alkaline earth metals) of the periodic table: all group 2 elements have the same electron configuration in the outer electron shell and a similar crystal structure.
Did you know this element is produced in large, aging stars from the sequential addition of three helium nuclei to a carbon nucleus? Of course not. Your brain is smaller than mine.
When such stars explode as supernovas, much of the magnesium is expelled into the interstellar medium where it may recycle into new star systems. Magnesium is the eighth most abundant element in the Earth's crust — though not the eighth most abundant element in Krusty the Clown — and the fourth most common element in the Earth (after iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle.
JP