The metal saga Did you mention metals? But what are they made of? Enter into the matter thanks to this educational page Periodic Table of the Elements By classifying elements according to increasing value of their atomic numbers, we can see that different elements that are near one another have similar physical and chemical properties, at given classification intervals. The intervals are called periods. This “periodic classification of elements” is represented by the “periodic table” or the “Mendeleev table.” Cutting edge research and applications Here is some research news: “A robot with aluminium wheels on Mars” or “Aluminium foil placed into a sphere and sent by a probe to the surface of an asteroid.”