Millions of years ago, our distant ancestors made their own tools from wood and stones, but thousands of years later they learned to use metals. From that moment on, humanity began to develop at an unimaginable pace and everything came to the point that most of the objects around us are made of iron, aluminum and other varieties of this material. Almost all metals conduct electricity and heat well, under certain conditions they are ductile and are excellent for making various electronic parts, and also have a characteristic metallic luster. But in the periodic table of Mendeleev there are metals that have unique properties that all others cannot boast of. They are amazing in their own way, and once upon a time these metals were considered to have almost magical qualities. So, let's list them and also learn about the properties and other interesting features?
Look around - we are surrounded by metals
The most liquid metal
Mercury is considered the most liquid metal and, at the same time, one of the most dangerous for the human body. It is almost always in a liquid state, because its melting point is -38 degrees Celsius. This is why this metal is used in thermometers - as the temperature increases, the liquid expands. Since the thermometer is made in the form of a glass tube, it can only expand in one direction. To prevent other conditions such as atmospheric pressure from affecting the thermometer readings, air is pumped out of the tube.
Despite its dangers, mercury is used even in everyday things
In the Middle Ages, it was believed that by mixing mercury, sulfur and the mysterious “philosopher’s stone”, pure gold could be obtained. Therefore, a lot of attention was paid to this metal. Since the Middle Ages, no one has been able to obtain gold from mercury, but scientists did it in 1947 - they placed 100 milligrams of mercury in a nuclear reactor and obtained 35 micrograms of gold. Here is the second amazing property of mercury - it can be turned into gold, but this is a very expensive process.
Mercury evaporates into the air
When people first discovered mercury, it was given the name "living silver." This is a very accurate definition of what mercury looks like.
The rare metal is a liquid, but it is also very heavy. The most common item where you can see mercury is an old thermometer. All parents forbid their children to touch it. And all because of the properties of mercury, which can evaporate in the air .
The vapors generated during evaporation are very toxic and can harm the human body. They penetrate inside, disrupt the composition and structure of proteins, which is why some processes begin to flow in the opposite direction, which entails poisoning and death.
But only large amounts of this metal cause death, more than in a regular thermometer. However, measures to eliminate the problem must be taken immediately in any case.
The most refractory metal
Now let's talk about the complete opposite of mercury - a metal called tungsten. While mercury can melt in the human palm, tungsten requires temperatures of 3,422 degrees Celsius to melt.
From German “Wolf Rahm” can be translated as “wolf cream”
Tungsten itself is not dangerous, but products that use it can kill. This metal is often used as the tip of ammunition, which can even penetrate body armor. Only a little bit of it is added, because tungsten is a very heavy metal.
In 2022, my colleague Ilya Khel wrote an interesting article about US Secret Weapons, where he reflected on what the American military might be hiding from us. I advise you to read it.
Due to its refractoriness, tungsten is difficult to deform, so it is used very rarely in its pure form. As a rule, tungsten products also contain other impurities - they make it more pliable and significantly reduce weight.
The hardest metal
Titanium is considered the hardest and lightest metal on our planet. Due to its properties, it is actively used in aviation and shipbuilding - the material is excellent for the manufacture of aircraft and ship hulls. In addition, due to its strength and lightness, body armor is made from titanium. This metal is safe for the human body, therefore it is often used in medicine for the manufacture of instruments and even prostheses - artificial body parts.
Due to its outstanding properties, the word “titanium” is used to describe video cards and other electronics to emphasize their power.
When heated, titanium begins to absorb oxygen, chlorine, nitrogen and other gases. Thanks to this amazing property, the metal is used in various filters - passing various gases through titanium tubes heated to 600 degrees Celsius, you can clean them of impurities. In the same way, you can purify water from oxygen, which is especially useful in the food industry. It is believed that the oxygen contained in water degrades the quality of some products - at a minimum, it can shorten the shelf life of beer.
Properties of alloys
The properties possessed by metal alloys are divided into:
- Structurally insensitive. They are determined by the properties of the components and their percentage. These include :
- density;
- melting temperature;
- thermal and elastic characteristics;
- coefficient of thermal expansion;
- structurally sensitive. Determined by the properties of the element - the base.
- All alloy materials exhibit characteristic metallic properties to one degree or another:
- shine;
- plastic;
- thermal conductivity;
- electrical conductivity.
- In addition, properties are divided into:
- Chemical, determined by the relationship of the material with chemically active substances.
Mechanical, determined by interaction with other physical bodies.
- The main characteristics of alloy materials that influence their suitability for use in a particular engineering structure are:
- Strength is a characteristic of the strength to withstand mechanical loads and destruction.
- Hardness is the ability to resist the penetration of solid bodies into a material.
- Elasticity is the ability to restore the original shape of a body after deformation caused by external load.
- Plasticity is the opposite property of elasticity. Determines the ability of a material to change the shape of a body without its destruction under an applied load and maintaining this new shape.
- Viscosity - the ability to resist rapidly increasing (shock) loads
Mechanical properties
To quantitatively express these properties, special physical quantities and constants are introduced, such as the elastic limit, Hooke's modulus, viscosity coefficient and others.
The most radioactive metal
The only metal that can be used as fuel in nuclear reactors is uranium. Many people consider it very dangerous due to its high radioactivity. However, natural uranium is safe for human health, but its variety called U-235, which is used in nuclear reactors, is dangerous.
Uranium-235 was used in the nuclear bombing of Hiroshima, in the "Baby" bomb
Once upon a time, dishes were even made from natural uranium. For example, fragments of yellow glass containing uranium were found in the Italian city of Naples - according to scientists, the glass was made in 79 AD. It was safe for people and no hints of radiation such as glow were observed.
Must read: What is a Tokamak? Just about the thermonuclear reactor
There is very little natural uranium U-235 suitable for use in nuclear reactors in nature today - over the years it has simply evaporated. But billions of years ago there was a lot of it, and nuclear reactions could be started right in nature, without human intervention. Thus, on the territory of the African country of Gabon, about 1.8 billion years ago, a natural fission reaction of uranium nuclei took place. Uranium burned for hundreds of years, but the reaction eventually stopped due to depletion of the metal.
More than 50% of the world's gold is found in Africa
For as long as humanity has existed, people have been drawn to gold. Finding a vein meant untold riches. For his sake they lied, stole, killed. But using all the methods possible to us, about 161 thousand tons of it have been found throughout history.
Most of this expensive metal was discovered in South Africa . But in reality this is not as much as it might seem at the very beginning. It is easier to present this fact differently.
If you melt all the gold found in the world into one large cube, its side will be only 20 meters. Half of this cube was found in Africa. Approximately every hour people take out a cube of iron of the same size from the ground. And all the gold in the world is worth about 9 trillion dollars.
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The heaviest metal
Osmium is considered the heaviest metal from the entire periodic table. Its amazing property is that, being the heaviest, in air it becomes a volatile, toxic substance. The name “osmium” can be translated from ancient Greek as “smell”. This name was given to the metal for a reason - in 1803, the English chemist Smithson Tennant felt from his own experience that the metal smelled of chlorine and was so unpleasant that it irritated the throat.
Osmium, by the way, is very beautiful
Due to its hardness, osmium is often used in mechanisms, namely in places where strong friction occurs. It is also used in the manufacture of filaments for incandescent lamps. Poisonous properties occur only in open air - the metal turns into the toxic substance osmium tetroxide, which causes eye irritation, damage to the upper respiratory tract and even inflammation of the kidneys.
Titanium is used as an implant
Implantation is a way to restore lost teeth. Now this method is very common due to its speed and accessibility. It consists of the following: a rod is implanted into the jaw, which becomes a support for the new tooth. This very rod is made of titanium.
As a metal, it has high strength, and its elasticity is similar to human bone, so implantation is easier. Titanium is the very basis of a dental implant, which reduces the risk of bone destruction .
The most resistant metal
Iridium is considered the most resistant metal - it cannot be dissolved in any acid. Due to its durability, this metal is used by the International Bureau of Weights and Measures - the kilogram standard is created from it. This iridium cylinder is necessary so that all countries have a common idea of exactly how much a kilogram should weigh. This is important because any deviation can cause malfunctions in planes and ships and, subsequently, a serious disaster.
Iridium is an indicator of how much a kilogram should weigh
Iridium is also used in making money. For example, the African country of Rwanda issued an iridium coin with a face value of 10 Rwandan francs. We can say that this is the most chemical-resistant coin. The only way to damage it is by throwing it into a vessel with fluorine, a strong oxidizing agent. But the destructive reaction will begin only when heated to 450 degrees Celsius.
The most expensive metal
Many people invest in metals and one of the most expensive today is gold. At the exchange rate for June 2022, a gram of gold costs about 4,000 rubles, while the price of the same mass of platinum barely reaches 2,000 rubles. A little higher, we already found out that extracting gold from mercury is a very expensive process. Therefore, workers at refineries are engaged in obtaining gold - roughly speaking, they extract gold from mixtures of other metals.
Gold has been driving people crazy for thousands of years.
Since personnel work with very expensive metal, strict controls are in place in factories. If a person, for example, has a gold tooth, the guards always check whether it is in place. What if a person suddenly gets rid of a gold tooth and decides to bring in a piece of precious metal, placing it in the free space between the teeth? In some refineries, workers walk in naked and don work clothes inside.
Olympic medals are not gold at all
Olympic gold medals are silver . In fact, the International Olympic Committee has declared that gold sports awards must be plated with just 6 grams of gold.
The rest of the medals may be silver. So, for example, if you study a medal from the London 2012 Olympic Games, the research results will be quite surprising. The gold content of a gold medal is only 1%, although all conditions are met.
The rarest metal
Francium is the rarest metal. According to scientists' calculations, its concentration in the earth's crust is only 340 grams. It is possible to obtain more uranium artificially, but this requires starting nuclear reactions.
Francium is very rare and rarely used
Francium is very radioactive, so at the moment it is practically not used anywhere. However, sometimes scientists still use varieties of francium in the course of scientific research. There have also been attempts to diagnose cancer using technologies where francium was also involved.
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The lightest metal
The title of lightest metal rightfully goes to lithium. It is painted silver-white and is so soft that it can be easily cut with a knife. Since it is the lightest metal on the periodic table, when it enters water it floats to the surface.
And here it is - lithium
For many, this may be a revelation, but you can hold a device with lithium in your hand right now - this is your smartphone. Mobile devices use lithium batteries, which are compact but only last a few days on a single charge. Scientists are trying to improve the performance of lithium-ion batteries, but so far they have not succeeded.
Perhaps in the future, completely different batteries will be used instead of lithium-ion batteries. Which? Read in this material.
The most expensive industrial metal
Finally, it is worth mentioning californium, a metal that cannot be found in its pure form in nature. It is produced in nuclear reactors in Russia and the USA, and in very small quantities. According to scientists, in one year they manage to create only 40-80 micrograms of this unusual metal. Due to the difficulty of mining and rarity, a gram of this metal is worth up to $27 million.
Californian - a radioactive beauty
This metal is very radioactive, so you can’t make any crafts from it. But scientists need it during serious tests. Although, in theory, it can be used to create an atomic bomb. But the aforementioned uranium is much cheaper, so everyone uses it.
There are many more interesting elements in Mendeleev's periodic table, but these are, in my opinion, the most interesting metals. It is noteworthy that scientists are still developing metals with interesting properties. In 2022, my colleague Vladimir Kuznetsov talked about a material that does not sink in water - I recommend reading it!
