Aluminum
Aluminum, chemical symbol Al, is a silvery-white colored and lightweight metal that is corrosion-resistant, non-magnetic and malleable. It is also ductile, meaning that it can be hammered into thin sheets and drawn out into wire. Aluminum is used where a lightweight and corrosion-resistant construction is needed, such as bike frames, and is also used in more general consumer products such as soda cans and aluminum foil. The main source of aluminum is bauxite.
Oxygen
Oxygen, chemical symbol O, is a colorless as well as odorless gas. Of all the chemical elements, oxygen is the most abundant in the earth's crust. Oxygen is an important part of life on earth, as many plants and animals need oxygen to survive. Oxygen is also needed to cause combustion, a necessary part of certain chemical reactions.
Titanium
Titanium, chemical symbol Ti, is a strong, silvery-colored metal that is, like aluminum, lightweight and corrosion-resistant. It is considered a good refractory metal, as it doesn't melt easily. Titanium is mainly used as an alloy ingredient for space-faring constructions. The main sources of titanium are rutile and ilmenite.
Iron
Iron, chemical element Fe, is silvery-white metal with a lustrous shine that is malleable and magnetic, and is the fourth most abundant element in the earth's crust. Unlike aluminum and titanium, iron is a heavy metal. However, like aluminum and titanium, iron is ductile. Iron is used in the construction industry as part of building infrastructures, and is also used by old-time blacksmiths and science teachers. The main sources of iron are hematite, magnetite and limonite.