Chlorophyll, which green plants use in photosynthesis, contains magnesium. Plants produce carbohydrates, a class of foods essential to living things, by means of photosynthesis. Magnesium also activates many of the enzymes that speed up chemical reactions in the human body. Magnesium and its alloys are used in manufacturing many products. Their light weight makes them suitable for aircraft and automobile parts and for tools and equipment.
Most magnesium alloys contain aluminum and zinc.
These materials make magnesium alloys stronger and easier to shape. Some alloys may also contain small amounts of such elements as manganese, thorium, and zirconium that provide other properties. Magnesium is used for a variety of nonstructural purposes because it is extremely active chemically. For example, pieces of magnesium are placed next to buried steel pipelines and water tanks. If magnesium were not present, oxygen and other chemicals in the earth would corrode the steel.