Madame Curie examined the radioactivity of many mineral samples one by one. Hundreds of substances have been tested, none of which is radioactive. But when she examined a pitchblende and a copper-uranium mica, she found that they were very radioactive, and their intensity was far greater than that predicted by the content of uranium or thorium in them. She also synthesized copper-uranium mica by herself according to the components obtained from the accurate analysis of natural copper-uranium mica ore, and found that the radioactivity of natural copper-uranium mica was 4.5 times that of synthetic samples. The abnormal radioactivity of these two minerals can only be explained as containing some new elements with little content but much stronger radioactivity than uranium and thorium.
1in June, 896, the curies began to cooperate to find this new element. They went to pitchblende first. After they decomposed the ore, they used systematic chemical analysis programs to gradually separate the various elements in the ore into groups. After each step of separation, the radioactivity of the two parts is measured, and the new element is determined in which part according to whether the solution and sediment are radioactive or not. After several exclusions, the search scope gradually narrowed, and finally they found that there were two radioactive elements in pitchblende, not a new one. 1in July, 898, they confirmed the existence of a new radioactive element according to radioactivity. At that time, they only got a little bit of bismuth sulfide enriched with this new element, which is much more radioactive than metallic uranium. To know that the content of this new element in pitchblende is only 100 million, how difficult it is to enrich it with general chemical methods! Mary named this new element "polonium" in memory of her native Poland. Five months later, the Curies discovered another new radioactive element based on radioactivity, which was concentrated in barium chloride crystal. This crystal mixed with new elements is 900 times more radioactive than metallic uranium. The Curies named this element "radium", which means "radioactive substance". Polonium is enriched in bismuth sulfide precipitation and radium in barium chloride crystal, which shows that their chemical properties are very similar to bismuth and barium respectively, but far from uranium. However, at this time, the Curies did not get any pure radium or polonium compounds. They decided that the next step was to prepare pure radium compounds from pitchblende. They estimate that after uranium is extracted from pitchblende, polonium and radium may remain intact in the waste residue, because the chemical properties of polonium and radium are far from uranium. Therefore, they bought cheap waste residue from Austrian state-owned mines to treat pitchblende. From 1899 to the end of 1902, Curie and his wife worked hard in the mine rot shed of physics school for 45 months, and treated two tons and one kilogram of waste residue at a time. After millions of times of dissolution, precipitation and crystallization, only 100 mg of optically pure radium chloride was finally obtained. Its radioactivity is surprisingly powerful, two million times that of uranium salt! When put into a glass bottle, the glass bottle will emit purple fluorescence, and it can also make diamonds, rubies, fluorite, zinc sulfide, platinum barium cyanide and so on emit phosphorescence. They preliminarily determined the atomic weight of radium, which is about 225, thus determining that it is below the barium group IIA in the periodic table.
1903 On June 25th, 36-year-old Madame Marie Curie passed the defense of her doctoral thesis at the University of Paris, the topic of which was "Research on Radioactive Substances". This year 1 1 month, the Royal Society awarded the Curie couple a gold medal for carrying dimensions. 1February 10, Curies and Bekkerel won this year's Nobel Prize in Physics and shared it.
19 10, Madame Curie cooperated with French chemist Billner (A. 1874- 1949) to obtain metal radium by electrolysis, and its properties were studied. 19 1 1 year, Madame Curie won the Nobel Prize in chemistry. Only a few scientists in the world have won the Nobel Prize twice, and Madame Curie is the only female scientist among them.
Marie Claudot fusca was born in Warsaw under Russian rule on 18671July 7, when Poland had been conquered for more than one hundred years. She had a strong patriotic thought when she was a teenager, and fell in love with science in her youth, determined to revitalize the motherland with science and win glory for Poland. She came to Paris to study in 189 1, and successively obtained a master's degree in mathematics and physics with excellent results. 1895, she married Curie, who was already a professor of physics at that time, and formed a pair of famous scientific partners. From/kloc-0 to June, 898, I decided to cooperate with Mary to explore new radioactive elements in pitchblende. Their close cooperation lasted for 8 years. 1906 One day, Curie was knocked down by a truck in the street, and the wheel took his life. Madame Curie was devastated and almost insane. As soon as she recovered after a long rest, she not only shouldered the family burden of raising two daughters with amazing perseverance, but also served as Professor Curie at the University of Paris, making great contributions to the establishment and development of radiation science, thus winning the Nobel Prize in Chemistry of 19 1 1 year. The discovery of radium triggered a revolution in the scientific field, and the work of the Curie couple was the beginning of the application research of atomic energy. But Madame Curie is not only one of the scientists who made great contributions, but also a noble and selfless person. Radium was expensive at that time, but Madame Curie was willing to live a simple life. She published the extraction method of radium without reservation and did not apply for a patent. As she said, "Radium should not make anyone rich. Radium is a chemical element and should belong to everyone. " Almost all the huge bonuses she won were used to help poor students or support scientific groups. 1934 On July 4th, Madame Curie died after suffering from pernicious anemia and leukemia for a long time. The doctor's certificate is: "The sinner who really took Madame Curie's life was radium". She devoted herself to science.