Autor: Wallid Guergour
Metallon, in Greek, metallum, in Latin, was the mine, the vein. In other words, metal is a natural product extracted from the earth. For a long time, men used it without knowing its secrets. Since the 18th century and scientific progress, things have been different. New metals and alloys have appeared, more adapted to the development of mankind. Look around you, today, metal is everywhere, on your wrist, near your plate, in the wheels of your bicycle, at the heart of the computer with which you read this book.... And even where you don't expect it, in the sculptures where it imitates nature. Metal is quite a story. In our region, there are many testimonies. It's up to you to discover them.
Between elements and metal
What is an element? It is the basis of all matter, yes, everything is made of chemical elements, water, air, wood, plants, stones, people, animals.... Each of these elements is characterised by its atom. At present, 118 elements are known. In addition to the 90 natural elements, isolated on earth or detected in the universe, there are 22 man-made elements. For example, plutonium. The atom is the element's identity card. It has its own symbol: it is the abbreviation of its name. It has a special number that corresponds to the number of electrons: an atom is a nucleus surrounded by electrons.
Periodic table of elements.
In 1869, the russian chemist and professor Dmitri Ivanovitch Mendeleïev wondered how to talk to his students in chemical elements known at the time. To evoke them in turn? What a drag! By dint of racking his brains, the chemist ended up classifying them into families and drew up a table. The strongest part of this story is that this table is still in use: Mendeleïev felt that more discoveries would be made and so he provided free boxes.