What is metal? The nature of this substance was interested in antiquity. Now about 96 types of metals are discovered . We will talk about their characteristics and properties in the article.
What is metal?
The largest number of elements in the periodic table relates to metals. Currently, only 96 of their species are known to humans. Each of them has its own characteristics, many of which have not yet been studied.
What is metal? This is a simple substance, which is characterized by large electrical and thermal conductivity, a positive temperature coefficient of conductivity. Most metals have high strength, ductility and forging. One of the distinguishing features is the presence of metallic luster.
The meaning of the word "metal" is associated with the Greek métallion, where it means "digging out of the ground", as well as "mine, mine." It came into Russian terminology during the reign of Peter I from the German language (German Metall), into which the word moved from Latin.
Physical properties
Elements metals usually have good ductility, with the exception of tin, zinc, manganese. In terms of density, they are divided into light (aluminum, lithium) and heavy (osmium, tungsten). Most have a high melting point; the general range ranges from - 39 for mercury to 3410 degrees Celsius for tungsten.
Under normal conditions, all metals except mercury and France are solid. The degree of their hardness is determined in points on the Moss scale, where 10 points are considered the maximum. So, tungsten and uranium are the hardest (6.0), cesium (0.2) is the softest. Many metals have silver, bluish and gray hues, only some are characterized by yellow and reddish colors.
In their crystal lattices are moving electrons, so that they perfectly conduct electric current and heat. Silver and copper do best with this. Mercury has the lowest thermal conductivity.
Chemical properties
By chemical properties, metals are divided into many groups. Among them are alkaline, alkaline earth, lungs, sea anemone and actinides, lanthanum and lanthanides, semimetals. Separately, there are magnesium and beryllium.
As a rule, metals act as reducing agents for non-metals. They have different activity, therefore, reactions to substances are not the same. Alkali metals are the most active ; they easily interact with hydrogen and water.
Under certain conditions, the interaction of metals with oxygen almost always occurs. Only gold and platinum do not react to it. They also do not react to sulfur and chlorine, unlike other metals. The alkaline group is oxidized in an ordinary environment, the rest when exposed to high temperatures.
Being in nature
In nature, metals are found mainly in ores or compounds, for example, oxides, salts, carbonates. Before use, they go through lengthy cleaning steps. Many metals accompany mineral deposits. So, cadmium is part of zinc ores, scandium and tantalum are adjacent to tin.
Immediately in its pure form, only inert, that is, inactive metals are found. Due to their weak susceptibility to oxidation and corrosion, they won the title of noble. These include gold, platinum, silver, ruthenium, osmium, palladium, etc. Noble metals are very plastic and have a characteristic bright shine in finished products.
Metals surround us everywhere. In large quantities, they are in the earth's crust. The most common are aluminum, iron, sodium, magnesium, calcium, titanium and potassium. They are found in sea water (sodium, magnesium), are part of living organisms. In the human body, metals are present in bones (calcium), in the blood (iron), the nervous system (magnesium), muscles (magnesium) and other organs.
Study and use
What is metal still knew ancient civilizations. Among the Egyptian archaeological finds dating from 3-4 millennia BC, precious metal products were found. The first people discovered gold, copper, silver, lead, iron, tin, and mercury. They served for the manufacture of jewelry, tools, ritual objects and weapons.
In the Middle Ages, antimony, arsenic, bismuth, and zinc were discovered. They were often given magical properties, associated with space, the movement of planets. Alchemists conducted numerous experiments in the hope of converting mercury into water or gold. Gradually, the number of discoveries increased, and by the 21st century all the metals known to date were discovered.
Now they are used in almost all areas of life. Metals are used for the manufacture of jewelry, machinery, ships, cars. They make frames for the construction of buildings, make furniture, various small parts.
Excellent electrical conductivity made the metal indispensable for the manufacture of wires, it is thanks to it that we use electric current.