The six elements in the alkaline earth metals group all have a variety of different uses, including making batteries, flashbulbs, fireworks, fertilizers and various metal alloys. The six alkaline earth metals are calcium, magnesium, barium, beryllium, radium and strontium.
Magnesium is one of the most widely used alkaline earth metals, and is used to create a number of lightweight alloys for various applications, including in constructing airplanes and spaceships. The highly reactive nature of magnesium is also the reason it is found in most fireworks.
Calcium is the only other alkaline earth metal that has a wide range of uses. Calcium is one of the primary components of plant and animal life, making it useful as a fertilizer and an additive to many foods. It is also used to help remove impurities from steel and can be found in many pharmaceuticals, papers and cosmetic products.
Barium and strontium are the only alkaline earth metals that don't play a role in industrial applications, although strontium is sometimes used in fireworks due to the bright orange color it produces when burned. Barium, radium and beryllium are all highly radioactive, which limits much of their usefulness. However, radium and beryllium do play a role in x-ray machines and also in detecting x-rays, while barium was formerly used in a number of medical applications until safer radioactive materials were discovered.