Chemical and Physical Properties of Magnesium. Magnesium is one of the most important elements that is present in many compounds as well as alloys. It is widely used as a chemical reagent, desulfurization agent, and vital ingredient in fireworks.It finds multiple applications due to its unique chemical and physical properties.s mentioned in the chemical properties, magnesium is also present in many other compounds like dolomite, magnesium carbonate (that is also known as magnesite), and magnesium sulfate (which is also known by the name epsomite).