Magnesium

Magnesium free metal burns with a characteristic brilliant-white light. The metal is now obtained mainly by electrolysis of magnesium salts obtained from brine and is used primarily as a component in aluminium-magnesium alloys. Magnesium is less dense than aluminium, and the alloy is prized for its combination of lightness and strength. Magnesium compounds are used medicinally as common laxatives, antacids (e.g., milk of magnesia)