When people hear the word "metal", it is usuallyis associated with a cold and solid substance conducting an electric current. However, metals and their alloys can differ very much among themselves. There are those that belong to the heavy group, these substances have the highest density. And some, for example, lithium, are so light that they could float in the water, if only they did not actively react with it.
Which metals are the most active?
But what kind of metal shows the most intenseproperties? The most active metal is cesium. By activity among all metals, he ranks first. Also, his "brethren" are France, which is on the second place, and uninitiated. But little is known about the properties of the latter.
Cesium properties
Cesium is an element that, like metalgallium, it is easy to melt in the hands. To do this, it is true, it is possible only under one condition: if the cesium is in a glass ampoule. Otherwise, the metal can quickly react with the surrounding air - it will ignite. And the interaction of cesium with water is accompanied by an explosion - this is in its manifestation the most active metal. This is the answer to the question of why it is so difficult to place cesium in containers.
In order to place it inside the tube, it is necessary that it be made of special glass and filled with argon or hydrogen. The melting point of cesium is 28.7 aboutFROM.At room temperature, the metal is in a semi-liquid state. Cesium is a substance of golden-white color. In the liquid state, the metal reflects light well. Cesium vapor has a greenish-blue hue.
How was the cesium discovered?
The most active metal was the first chemicalelement, the presence of which in the surface of the earth's crust was detected using the method of spectral analysis. When scientists received a spectrum of metal, in it they saw two lines of sky-blue color. Thus, this element has its name. The word caesius in Latin means "sky blue".
History of discovery
Its opening belongs to German researchersR. Bunsen and G. Kirchhoff. Even then, scientists were interested in what metals are active and which are not. In 1860, researchers studied the composition of water from the Durkheim reservoir. They did this with the help of spectral analysis. In a sample of water, scientists discovered elements such as strontium, magnesium, lithium, calcium.
Then they decided to analyze a drop of water athelp of the spectroscope. Then they saw two bright blue lines that were not far from each other. One of them in its position practically coincided with the strontium metal line. The scientists decided that the substance discovered by them is unknown and attributed it to the group of alkali metals.
In the same year, Bunsen wrote a letter to hiscolleague-photochemist G. Roscoe, in which he talked about this discovery. And officially about cesium was reported May 10, 1860 at a meeting of scientists at the Berlin Academy. Six months later, Bunsen was able to extract about 50 grams of cesium chloroplatinite. Scientists recycled 300 tons of mineral water and allocated about 1 kg of lithium chloride as a by-product in order to eventually obtain the most active metal. This suggests that there is very little cesium in mineral waters.
The complexity of obtaining cesium is constantly pushedscientists on the search for containing minerals, one of which is the pollucite. But the extraction of cesium from ores is always incomplete, during the exploitation of cesium it dissipates very quickly. This makes it one of the most difficult substances in metallurgy. The earth's crust, for example, contains 3.7 grams of cesium per ton. And in one liter of sea water, only 0.5 μg of the substance is the most active metal. This leads to the fact that the extraction of cesium is one of the most labor-intensive processes.
Receiving in Russia
As indicated, the main mineral from whichget cesium, is the pollucite. And also this most active metal can be obtained from a rare avogadrite. In the industry it is polulzit. Its extraction after the collapse of the Soviet Union in Russia was not carried out, despite the fact that even in those days, giant cesium reserves were discovered in the Voronaya tundra near Murmansk.
By the time when the domesticthe industry was able to afford the extraction of cesium, the license to develop this field was acquired by the company from Canada. Now the extraction of cesium is produced by the Novosibirsk company CJSC "Rare Metals Plant".
The use of cesium
This metal is used for manufacturingdifferent photocells. As well as cesium compounds are used in special branches of optics - in the manufacture of infrared instruments, binoculars of night vision. Cesium is used in the manufacture of sights, which allow you to notice the technique and the living force of the enemy. It is also used for making special metal halide lamps.
But this does not exhaust the range of its application.Based on cesium, a number of medications have also been developed. These are medicines for the treatment of diphtheria, ulcers, shocks and schizophrenia. Like lithium salts, cesium salts have normotimic properties - or, simply, are able to stabilize the emotional background.
Metal of France
Another of the metals with the most intenseproperties is france. It received its name in honor of the motherland of the discoverer of metal. M. Peret, born in France, discovered a new chemical element in 1939. He belongs to the number of such elements, which even the chemists themselves find it difficult to draw any conclusions.
France is the heaviest metal.At the same time, the most active metal is France, along with cesium. This rare combination - high chemical activity and low nuclear stability and possesses france. Its longest-lived isotope has a half-life of only 22 minutes. France is used to detect another element - actinium. And also the salt of France used to be used to detect cancerous tumors. However, because of the high cost of this salt is unprofitable to produce.
Comparison of the most active metals
Unbound is not yet an open metal.He will occupy the first place in the eighth line of the periodic table. The development and research of this element is being conducted in Russia at the Joint Institute for Nuclear Research. This metal will also have very high activity. If we compare already known france and cesium, then the highest ionization potential - 380 kJ / mol - will have france.
In cesium, this figure is 375 kJ / mol.But France reacts not so fast as cesium. Thus, cesium is the most active metal. This is the answer (chemistry is often the subject in the program of which you can find a similar question), which can be useful both in the classroom and in the vocational school.
