For 10 points, name this alkaline earth metal with symbol Mg.
This element reacts with titanium tetrachloride in the Kroll process. Certain compounds containing it exist in a Schlenk equilibrium; those compounds consist of this element and an alkyl or aryl halide, Grignard reagents. Active ATP molecules must be bound to this metal's 2+ ion. It is able to burn even when encased in dry ice, and when burning in air it produces a brilliant white light. Its hydroxide has a milky-white appearance and is used as an antacid, while its sulfate is called Epsom salt. For 10 points, name this alkaline earth metal with symbol Mg.
This element reacts with titanium tetrachloride in the Kroll process.
{magnesium} [prompt on {Mg} before mentioned]