Metals are made up of those chemical elements that are to the left and below a dividing line from boron to astatine in the periodic table of elements. The metallic character increases from top to bottom or from right to left. The non-metals are at the top right, with the semi-metals in between. The transition group elements are without exception metals. These are about 80% of the chemical elements. The transition to the non-metals via the semi-metals is fluid here.
The term metal is often also used for alloys, intermetallic phases and the metallic modifications of non- or semi-metals. The prerequisite for this is that they have certain typical metallic material properties in solid or liquid form. These are based on the fact that the atoms in question are held together by the metallic bond. Their most important feature are the freely movable electrons in the lattice.
Metals have been used as materials in a variety of ways since the beginning of civilization. Physicists and materials scientists deal with the term metal physics (also metallurgy) with all the basics and with applications of metal.
Metals are traditionally divided into heavy metals and light metals according to their density. According to the reactivity into precious metals and base metals. Belonging to the main and subgroups of the periodic table is also important for the chemical behavior.
The compounds or solutions of different metals with each other or in each other are called alloys. Except for the manufacture of electrical cables, pure metals are practically not used because they have the greatest conductivity. Here unalloyed metals such as v. a. copper and aluminum used.
The core of the earth consists largely of iron, while non-metals predominate in the earth`s crust. Particularly common metals are aluminium, iron, manganese, titanium, calcium, magnesium, sodium and potassium. However, many rare metals are highly enriched in their mining sites. Ores are rocks that contain classic metals in mineable concentrations.
A world without metals would be impossible today, it is not without reason that the development phases of mankind are divided into the Stone Age, Bronze Age or Iron Age according to the materials used.