What is metal? The nature of this substance has been of interest since ancient times. About 96 types of metals have been discovered so far. We will talk about their characteristics and properties in the article.
What is metal?
The largest number of elements in the periodic table refers to metals. Currently, only 96 of their species are known to man. 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 high electrical and thermal conductivity, a positive temperature coefficient of conductivity. Most metals have high strength, ductility and can be forged. One of the distinguishing features is the presence of a metallic sheen.
Meaning of the word "metal" is associated with the Greek métallion, where it means "to dig out of the earth", as well as "mine, mine". It came to Russian terminology during the reign of Peter I from the German language (German: Metall), into which the word moved from Latin.
Physical properties
Metal elements usually have good ductility, with the exception of tin, zinc, manganese. By density, they are divided into light(aluminum, lithium) and heavy (osmium, tungsten). Most have a high melting point, with a general range ranging from -39 degrees Celsius for mercury to 3410 degrees Celsius for tungsten.
Under normal conditions, all metals except mercury and francium are solid. The degree of their hardness is determined in points on the Moss scale, where the maximum is 10 points. So, the hardest are tungsten and uranium (6.0), the softest is cesium (0.2). Many metals have silver, bluish and gray hues, only a few are yellow and reddish.
Mobile electrons are in their crystal lattices, thanks to which they are excellent conductors of electric current and heat. Silver and copper work best with this. Mercury has the lowest thermal conductivity.
Chemical properties
Metals are divided into many groups according to their chemical properties. Among them are alkaline, alkaline earth, light, actinium and actinides, lanthanum and lanthanides, semimetals. Magnesium and beryllium are found separately.
As a rule, metals act as reducing agents for non-metals. They have different activities, so the reactions to substances are not the same. The most active are alkali metals, they easily interact with hydrogen, 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 alkali group is oxidized toordinary environment, the rest when exposed to high temperatures.
Being in nature
In nature, metals are found mainly in ores or compounds, such as oxides, s alts, carbonates. They go through lengthy cleaning steps before being used. Many metals accompany mineral deposits. So, cadmium is part of zinc ores, scandium and tantalum are adjacent to tin.
Only inert, that is, inactive metals, are found immediately in their pure form. Due to their low susceptibility to oxidation and corrosion, they won the title of noble. These include gold, platinum, silver, ruthenium, osmium, palladium, etc. Noble metals are very ductile and have a characteristic bright sheen in finished products.
Metals are all around us. They are found in large quantities 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 found in bones (calcium), blood (iron), nervous system (magnesium), muscles (magnesium) and other organs.
Learning and using
Ancient civilizations knew what metal was. Among the Egyptian archaeological finds dating back to 3-4 millennia BC, items made of precious metals were found. The first man discovered gold, copper, silver, lead, iron, tin, mercury. They were used to make jewelry, tools, ritual items and weapons.
In the Middle Ages, antimony, arsenic, bismuth, zinc were discovered. They were often given magical properties, associated with the cosmos, the movement of the planets. Alchemists carried out numerous experiments in the hope of turning mercury into water or gold. Gradually, the number of discoveries increased, and by the 21st century, all metals known to date were discovered.
Now they are used in almost all spheres of life. Metals are used to make jewelry, equipment, ships, cars. They are used to make frames for the construction of buildings, furniture, and various small parts.
Excellent electrical conductivity has made the metal indispensable for the manufacture of wires, it is thanks to him that we use electric current.
