More than 20 years later, Ramsey confirmed that helium also exists on the earth. 1895, American geologist Hilbrand observed that heating yttrium uranium ore in sulfuric acid would produce a gas that could not spontaneously ignite or support combustion. He thought the gas might be nitrogen or argon, but he didn't continue his research. After Ramsey knew about the experiment, he repeated the experiment with yttrium uranium ore and got a small amount of gas. When testing gas by spectral analysis, I thought I could see the spectral line of argon, but I accidentally found a yellow line and several weak bright lines of other colors. Ramsey compared it with the known spectral lines, and none of them were similar to it. Thinking hard, I finally remembered the helium found on the sun 27 years ago. The spectrum of helium is yellow line. If these two yellow lines can overlap, the gas released by yttrium uranium mine should be solar element helium. Ramsey was very cautious and asked crookes, the most famous spectroscopy expert in Britain at that time, to help him check and confirm that the unknown gas Ramsey obtained was the "solar element" gas. 1895 In March, Ramsey first published a briefing on the discovery of helium on the earth in Chemical News, and this discovery was officially announced at the annual meeting of British chemistry in the same year. Later, people found helium in the atmosphere, water, natural gas, liquefied petroleum gas, uranium and other minerals, and even meteorites. 1902, dmitri mendeleev accepted the discovery of helium and argon, and these rare gases were included in his element arrangement and classified as group 0, from which the periodic table of elements evolved.
Ramsey continued to use fractionation to separate liquid air into different components in order to find other rare gases. He found three new elements in 1898: krypton, neon and xenon. Krypton comes from the Greek "ζξυυυ (kruptó s)", which means "hiding"; Neon comes from the Greek word νο(néos), which means "new"; Xenon comes from the Greek ξνο(xénos), which means "stranger". Radon was discovered by Friedrich Ernst Dunn in 1898. It was originally named radium radiation, but it was not listed as a rare gas at that time. It was not until 1904 that its characteristics were similar to those of other rare gases. 1904, Rayleigh and Ramsey won the Nobel Prize in Physics and Chemistry respectively in recognition of their discoveries in the field of rare gases. Sid blom, chairman of the Swedish Academy of Royal Sciences, said in a speech: "Even if the predecessors failed to identify any element in this family, they can still find a new family of elements, which is unique in the history of chemistry and has essential special significance for scientific development."
The discovery of rare gases is helpful to deepen the comprehensive understanding of atomic structure. 1895, French chemist Henri Moissan tried to make fluorine (the most electronegative element) react with argon (a rare gas), but failed. Until the end of the 20th century, scientists were still unable to prepare argon compounds, but these attempts promoted the development of new atomic structure theory. Based on these experimental results, Danish physicist niels bohr proposed in 19 13 that the electrons in atoms are arranged around the nucleus in the form of electron shells, and the outermost electron shells of all rare gas elements except helium always contain 8 electrons. In 19 16, Gilbert Newton-Lewis formulated the octahedral rule, pointing out that the eight electrons in the outermost electron layer are the most stable arrangement of any atom; This electronic configuration prevents them from reacting with other elements because they don't need more electrons to fill their outermost electron shell.
But in 1962, Neil bartlett discovered the first rare gas compound xenon hexafluoroplatinate. Other rare gas compounds were subsequently discovered: Radon difluoride, a compound of radon, was found in1962; In 1963, the krypton compound krypton difluoride was discovered. In 2000, the first stable argon compound argon hydrogen fluoride (HArF) was successfully prepared at 40K(-233.2℃).
199865438+In February, scientists from Dubna United Nuclear Research Institute in Russia bombarded plutonium with calcium atoms, resulting in a single atom of the element 1 14, which was later named Fl. Preliminary chemical experiments show that this element may be the first overweight element. Although it is located in 14 family of the periodic table of elements, it has the characteristics of rare gas. From June 5438 to October 2006 10, scientists from the United States Joint Nuclear Research Institute and Lawrence Livermore National Laboratory successfully synthesized Uuo by bombarding californium with calcium atoms, which is the seventh element in the 18 family.
20 13 12 12 Two international scientific research groups studying supernova explosion debris reported in the American magazine Science that they discovered inert gas molecules for the first time in the universe and observed the formation of phosphorus, one of the six basic elements of life, in the explosion center of stars for the first time.
Mike Barlow, a professor at University College London, and his colleagues used the European Space Agency's Herschel Space Telescope to observe the crab nebula 6500 light-years away from the Earth in the far infrared band and found argon and hydrogen molecules. What they observed was the argon isotope argon 36, which was ionized by the energy emitted by the neutron star in the center of the crab nebula, and then formed argon-hydrogen molecules with hydrogen. This discovery also supports the theory that argon 36 isotope originated from the center of supernova.
In another study, South Korean and American researchers found a lot of phosphorus in Cassiopeia A, the youngest known supernova remnant in the Milky Way. Their observations with the 5-meter-diameter Hale telescope at Paloma Mountain Observatory in California show that the ratio of phosphorus to iron 56 isotope in Cassiopeia A is 100 times higher than that in other parts of the Milky Way, which indicates that phosphorus is also produced in supernovae.
Before 20 13, scientists had observed the origin of five other basic life elements in the universe: carbon, hydrogen, oxygen, nitrogen and sulfur.
About one hundred years after the discovery of nitrogen, the British chemist Rayleigh (J.W.S.1842-1919) got nitrogen by removing oxygen, carbon dioxide and water vapor from the air. On the other hand, nitrogen is produced by the decomposition of nitride. He compared the two nitrogen sources and found that the density of the former was 1.2572g/L and that of the latter was1.2508 g/L. Why is the density of nitrogen in the air higher? Is there any heavier inert gas in it? British chemist Ramsey (W.1852-1916) reacted with the nitrogen in the air by burning magnesium to remove the nitrogen in the air, leaving a small amount of rare gas. It is proved by spectral test that it is a new gas element called argon. In the next few years, he separated three other rare gases-neon, krypton and xenon-from crude argon by fractionation. 1895, Ramsar treated asphalt oil mine with sulfuric acid to produce a gas, which was identified as helium by spectrum. He was awarded the 1904 Nobel Prize in chemistry for his discoveries of helium, neon, krypton, argon and xenon.