[Pinyin]: [kÄi] [word meaning]: 1. An artificial radioactive element.
According to foreign media reports, from the far-reaching expanse of the universe to everything around us, it is composed of some of the simplest and most basic material-chemical elements. The first 26 elements of the periodic table, from hydrogen to iron, are all formed within the star's internal nuclear fusion process. Elements naturally present from the 27th element cobalt are formed due to the supernova explosion. And there are some elements that scientists have synthesized in the laboratory. Synthetic elements are a difficult task. Scientists may need more than ten years of experimentation and testing. They can only get a moment of joy, because some synthetic elements can only exist for a short period of time. The following are nine artificial synthetic elements that were born in the laboratory.
1, the first person to synthesize elements: é” (atomic number 43)
The Periodic Table of the Elements of Modern Chemistry was first compiled by the Russian scientist Dmitry Ivanovich Mendeyev in 1869. He arranged the 63 elements known at that time according to the atomic weight and arranged in the form of a table, and put elements with similar chemical properties on the same row. This is the embryonic form of the periodic table. But at the time, he encountered a problem and found that there was a missing element 43 between the molybdenum and hafnium elements. The element of this vacancy is helium because it is the element with the lowest atomic number that has no stable isotopes, because the element is unstable and has almost never been found on Earth. Until 1937, Italian physicist Carlo Peirier and Emilo Segre finally confirmed its existence. They used helium (heavy hydrogen) to bombard molybdenum to obtain the isotopes of helium, and subsequently obtained many isotopes of helium from the fission products of uranium. Scientists have now discovered all cesium isotopes with a mass of 90 to 110. Niobium is a silver-gray metal. Niobium 99 is the most widely used chemical nuclide in the clinical diagnosis of nuclear medicine. Only a small amount of strontium99 has been found in nature.
2. Rare earth elements obtained from nuclear reactors: helium (atomic number 61)
The Royal Society of Chemistry said that some of the stars in the constellation of the constellation of stars are found to have cesium.
The lanthanum element is another "alternative" of the periodic table, and its neighboring elements are stable, but it does not have its own stable isotope. In 1941, scientists in Ohio, the United States, used cerium and lanthanum to produce products that looked like element 61 in terms of attributes. However, in the 1940s it was very difficult to extract this rare earth metal. Therefore, the discovery of element 61 has been going on for several years, until scientists later obtained artificial methods from nuclear reactors.
3. Elements produced by the bombardment of uranium by neutrons: thorium (atomic number 93) and thorium (atomic number 94)
In 1940, scientists at the University of California, Berkeley, used neutrons to bombard uranium to obtain plutonium, which then went through a decaying process to transform it into plutonium. In 1941, scientists from the University of California, Berkeley made an important 239 isotope, an important raw material for the manufacture of atomic bombs. At the end of World War II, the atomic bomb that the United States invested in Japan's Nagasaki codenamed "fat" used nuclear power as its nuclear charge.
4. Accidental discovery of the first hydrogen bomb in the United States: helium (atomic number 100)
In 1952, U.S. scientists accidentally discovered plutonium-255 in the residue of the first hydrogen bomb test in the United States on the Pacific Ocean, and plutonium could be produced by bombarding transuranic elements with lighter particles or by neutron capture. It was named after the famous atom physicist and atomic bomb pioneer Enrico Fermi. Fermi devoted his entire life to the study of atomic physics theory, and he also made many experimental work in this field, and made outstanding contributions to the development of the theory of atomic bomb and nuclear reaction. In 1942, under his leadership, the world’s first nuclear reactor was built at the University of Chicago. On July 16, 1945 in Los Alamos, New Mexico, he led the successful test of the first atomic bomb. In addition, he also studied the sources of cosmic rays and also contributed to astrophysics. Fermi was awarded the Nobel Prize in physics in 1938 for his work on neutrons.
5. Radon used in smoke detection (atomic number: 95)
Scientists who have discovered thorium elements have conducted further research to create thorium elements. In 1944, scientists used neutrons to bombard é’š-239 and then produced é’š-240 and é’š-241. Since then, they have converted these neutrons into protons in the process of decay, thus obtaining element 95.é•…241 is currently used in smoke detectors.
6. The most expensive element in the world: one gram worth one billion US dollars (atomic number: 98)
Scientists also discovered the presence of niobium in the remnants of the hydrogen bomb test in 1952. However, niobium does not necessarily require a hydrogen bomb to produce it. As early as 1950, the American nuclear chemist Green - Xi Boge and others had used helium ions to bombard the plutonium and thus produced plutonium. This element is the most expensive element in the world and 1 gram is worth 1 billion dollars. The name is named after the California state of the United States because scientists who discovered it worked at the University of California, Berkeley. It does not exist in the earth's crust because of its nuclear instability. Until 1975, there were only about 1 gram of paralysis in the world. The most widely used is the cesium 252 isotope, which can release neutrons at an alarming rate, reaching 170 million per minute. This feature makes the helium element very dangerous, but it can be widely used in the analysis of the purity of gold and silver, detection of metal fatigue, start the nuclear reactor and mine detection and other aspects.
7, artificial radioactivity No. 106 elements:
With the advent of more powerful particle accelerators, scientists have discovered new ways of producing high-energy elements. In 1974, the American Lawrence Berkeley National Laboratory used their super-heavy ion linear accelerator to bombard yttrium-249 with oxygen 18 ions to make element No. 106. Element 106 is an artificial radioactive element, chemical symbol 106 or Unh, and four isotopes with mass numbers of 259, 260, 261 and 263 have been found.
8. Element 110 named after a German city
In 1994, scientists in Darmstadt, Germany, used nickel ions to bombard lead atoms to obtain a Titanium-269 atom with a half-life of only 0.17 milliseconds. In 2001, the International Federation of Theoretical and Applied Chemistry accepted the proposal of scientists to name the No. 110 chemical element first discovered by the scientists in the name of Darmstadt, calling it Darmstadtium, abbreviated as “Dsâ€. The element name will take effect from August 2003.
9, "New D" on the Periodic Table of the Elements: Element 112
In 1996, scientists from the German Institute of Heavy Ion Siegh-Hoffman and others used zinc ions to irradiate lead foil to create element 112. However, the atom of this element immediately declined, so Huffman only knew that they had created a new element. It was not until 2004 that a laboratory in Japan rediscovered this new element and only then verified the existence of element 112. The International Union for Pure and Applied Chemistry temporarily named this "overweight element" "Ununbium" and the word "ununbi" originated in Latin. The team of scientists led by Sigma-Hoffman is rigorously picking the right name.