Properties of metals

The vast majority of simple substances are metals. Physical properties of metals - it's opacity, specific "metallic" gloss, high thermal and electrical conductivity, and plasticity. It is thanks to these properties that metals played a decisive role in the history of mankind.

Physical properties of metals - it's opacity, specific metallic gloss, high thermal and electrical conductivity, and plasticity

What is the reason that metals have such properties and why are they so different from nonmetals? The periodic law and theory of atomic structure explained the structure and properties of metals. It turned out that the metallic properties of the elements are due to the electronic structure of their atoms.

Metals on the outer electron shells have 1-4 electrons. These electrons are mobile, since they are weakly attracted by the nucleus. Through this metals, all or some of the external electrons easily give up, resulting in positively charged ions-cations. The easier it is for metals to lose their electrons, the more active they are and the more pronounced their metallic properties.

In the atoms of nonmetals on the outer electron shells, there are many electrons 4-8, with the exception of hydrogen (1) and boron (3). These electrons are strongly attracted by the nucleus and therefore tearing them away from the atom is very difficult. But atoms of nonmetals can attach excess electrons and turn into negatively charged ions - anions.

All metals, except liquid mercury, under normal conditions Solid and have a crystalline structure. The properties of metals are closely related to the structure of their crystals. At the sites of the crystal lattice, atoms and ions (cations) are placed, and the number of ions and electrons in crystals varies from metal to crystal. External electrons, as they are mobile and weakly attracted by nuclei, form the so-called "electron gas", which "wanders" between ions in a crystal. "Electronic gas" does not belong to individual ions, but to the crystal as a whole. It is due to the presence of such mobile electrons in the crystal lattice of metals that their high electrical and thermal conductivity can be explained. "Electronic gas" reflects light very well (therefore, metals are opaque and have a characteristic luster), as well as short radio waves. The last property of metals is the basis of radar.

Metals can be forged and their ability to stretch is explained by the slip (displacement) of some layers of ions relative to others.

As already noted, the easier it is for metals to give away their valence electrons, the more active they are and, therefore, easier to enter into chemical reactions. More active metals displace less active compounds from their compounds. In addition, many metals displace hydrogen from certain acids, as well as from water. On this basis, all metals can be arranged in a so-called series of activities, or an electrochemical series of stresses.

Platinum metals, gold and silver have long been called noble. They are chemically quite inert, and therefore do not react with water or with many acids. Like precious metals, titanium, zirconium, hafnium, niobium, tantalum, molybdenum, tungsten and rhenium, which are also chemically passive, behave. They are heat-resistant and have remarkable mechanical properties. That is why these metals and their alloys play a huge role in modern aviation, rocketry and nuclear power engineering.

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