The most active metals are elements of groups I and II located on the left side of the periodic table. A metal is considered active when it reacts strongly and quickly with other elements. The reactivity of the metal increases as we move from the top to the bottom of the periodic table.
The exception is hydrogen, which is not considered a metal and is located in the upper left corner of the periodic system of chemical elements of Mendeleev.
The most active metals in the world
According to the reactivity of metal elements listed in the periodic table of chemical elements, they are divided into three groups:
- Active metals.
- The average activity of metals.
- Inactive metals.
The most active metals on Earth are lithium, cesium and France.
Cesium is the most active of non-radioactive elements. This is a rare silver-yellow shiny metal with an atomic number (number of protons in the nucleus) 55. It is a very soft element that will melt in your hands - if it does not explode earlier, as it reacts strongly to moisture.
There is also a very radioactive element, France, which may be more active than cesium. Or maybe not, we probably will never know, because France is not only extremely radioactive, but also an extremely rare metal.
The last of the three most active metals - lithium - has an interesting property. It gives raspberry color to flames.
Here is a video demonstration of the activity of lithium, sodium, potassium, rubidium and cesium.
What is cesium
Cesium refers to alkali metals. They are very reactive, and do not occur freely in nature. These metals are also very ductile, they are good thermal and electrical conductors.
Cesium was the first element that could be detected with a spectroscope. In 1860, it was discovered by German chemists Robert Bunsen and Gustav Kirchhoff when they analyzed the spectrum of mineral water from the Bad Dürkheim spring.
Cesium is found naturally in the minerals of pollucite and lepidolite. It is also found in many aluminosilicates such as beryl, petalite and carnallite. The richest known cesium deposits are located in Canada, on the shores of Lake Bernick Lake. About 70% of all land reserves are concentrated there. It is curious that this lake is the venue for the annual cesium festival (February 24), when tons of this substance are burned in the snow, and other cesium madness prevails.
Cesium is also a byproduct of nuclear fission in reactors.
Cesium properties
Although cesium is not the heaviest metal in the world, it is the most active and has a number of unique properties:
- It spontaneously burns in air and instantly explodes on contact with water or moisture in any form, even with ice up to -116 С.
- It burns with a brilliant blue flame. The flame seems purple to the uninitiated, not blue, but after sufficient meditation, study of the works on chemistry and blissful hours spent in awe before the cesium burns, the true blue nature of its flame is revealed
- The name "cesium" comes from two bright blue lines in its emission spectrum. Translated from Latin "caesius" means "sky blue."
- Its hydroxide (liquid molten state) is able to eat flesh, glass and many other substances. Only the rhodium metal and a number of its alloys are able to withstand the cesium hydroxide melt.
- Cesium iodide and bromide are used as central components in the production of high-precision optics, including sights, glasses and night vision binoculars. Cesium has also been experimentally used in ion power plants for spacecraft, due to its low ionization potential.
- Cesium is used to create the most accurate atomic clocks. Even the best watches in the world can lag behind for a few seconds or even a minute. But cesium-based atomic clocks lose only one second in five billion years.
- Natural cesium consists of one stable isotope, Cs 133. 30 other radioactive isotopes are known that fill the range from Cs 114 to Cs 145. Cesium-137 (aka cesium) is one of the most biohazard components of radioactive waste and nuclear fallout. It accumulates in living organisms and even in fungi, and its highest content is found in reindeer and waterfowl in North America.
Humans and animals are constantly exposed to minimal amounts of cesium when eating, breathing, and drinking. Although it is unlikely that we will be ill only due to cesium, prolonged exposure can lead to adverse health effects, including nausea, vomiting, bleeding, and cell damage.
Cesium and Cancer Treatment
Paracelsus claimed that everything is poison, and everything is medicine. It is only a matter of dosage. And when it comes to cesium, the words of Paracelsus are absolutely true.
Cesium's efficacy in treating several forms of cancer, including brain tumors, is currently under investigation. Cesium-131, the radioactive isotope of cesium, together with another radioactive isotope (iodine-125) is placed in a brachytherapy capsule (“seed”).
According to the American Society of Brachytherapy, a brachytherapy capsule is a radioactive “pod” that fits directly into cancerous tissue. Such seeds are effective in several forms of cancer, including cancer of the prostate, cervix, and endometrium.
In one study, a group of 24 patients with brain tumors were implanted with brachiotherapeutic seeds with cesium-131. Minimal side effects were noted, but in general, patients tolerated this form of treatment well.
The idea of using brachytherapy seeds with cesium-131 as a cancer treatment arose back in the 1960s and was described in a study published in the journal Radiology. A study published in the journal Medical Physics in 2009 discussed the use of cesium-131 seeds for the treatment of prostate cancer with positive results.
More research is needed before cesium treatment firmly takes its place in medicine. However, studies have so far proven that the use of cesium-131 for the treatment of cancer with brachiotherapy is encouraging.
Comparison of Cesium and France
Like cesium, France (Fr) belongs to alkali metals (only radioactive) and has an extremely high chemical activity.
- The density of France is 1.87 grams per cubic centimeter, which is comparable to the density of cesium - 1.879 grams per cubic centimeter.
- Cesium and France are two of the four metals that become liquid at room temperature. Mercury and gallium possess the same property.
- The interaction of cesium with water is very spectacular - with an explosion, the formation of hydroxide CsOH and hydrogen H2. France and water also do not really "love" each other, and when they interact, the strongest alkali is formed - France hydroxide.
- Like cesium, France accumulates in living organisms. Therefore, the isotopes of this metal have found their application in medicine, for the diagnosis of cancer and various biological studies.
- But the prevalence of cesium is far ahead of France. About 20 tons of cesium enriched ore are mined annually in the world. According to PeriodicTable, cesium is the 50th most common element of the earth's crust. France in the entire earth's crust, there are about 340 grams.
That is, by their properties, the two most active metals on the planet are very similar.
Comparisons of Cesium and Lithium
Lithium is in the top 3 most active metals on the planet. This is a key component in the batteries that power smartphones, laptops and electric cars. More than half of the world's lithium supplies come from the “lithium triangle” - Bolivia, Chile and Argentina. The largest source of lithium from salt is the Chilean desert of Atacama.
- Like cesium, lithium belongs to alkali metals. And, like cesium, it is found in nature only in the form of compounds. Moreover, traces of lithium are found in almost all igneous rocks and in many mineral springs. It was one of the three elements created by the Big Bang, along with hydrogen and helium.
- Lithium and cesium are scarce in the earth's crust - 21 g / t and 3.7 g / t, respectively.
- If cesium ignites in the air, interacting with oxygen, then lithium can even be stored outdoors for some time. Due to this “tolerance”, lithium is the only representative of alkali metals that does not require storage in kerosene. He can also convey “fiery greetings” when interacting with oxygen, but only at high temperatures.
- Lithium is the least dense metal (0.533 g / cm3). Cesium has a much higher density - 1,879 grams per cubic centimeter. The lightness of lithium means that it can store energy without adding gravity to various devices.
- But low-melting lithium gives odds to cesium. Its melting point is 180.5 degrees Celsius. And cesium melts already at 28.4 degrees Celsius.
- But lithium boils quickly - at 134 degrees, but bringing cesium to a boil is not easy, a temperature of 678 degrees is necessary.
- Both lithium and cesium are easily cut with an ordinary knife.
