Where does the periodic table of elements come from?

Earlier, we talked about the problem that ancient Greek philosophers devoted themselves to the origin of all things. Scholars worked hard for 1000 years, and it was not until lavoisier and Dalton made progress that chemistry became a scientific theory. Before Mendeleev, lavoisier decomposed natural substances into basic elements and made a series of experiments on the properties of elements. Finally, lavoisier put forward the first list of chemical elements in history. However, it should be noted that this time is not the periodic table of chemical elements. Because this table does not reflect periodicity. 1829, the german chemist d' urberville put forward the theory of three elements. In his time, man discovered 54 elements. Among these elements, D 'Urberville found that the average atomic weights of lithium and potassium are very close to sodium; The same thing happens between calcium, strontium, barium, sulfur, selenium, tellurium, chlorine, bromine and iodine. In other words, he found that the arrangement of elements was regular. Inspired by D 'Urberville's "Three Elements Theory" and combined with the characteristics of scales, Newlands arranged 6 1 elements known at that time in the order of increasing relative atomic mass. He found that in every seven elements, there would be elements with similar properties. Therefore, this is also called element octave. Thus, there is a periodic table of "element octaves". He published his findings in a paper, but was rejected and regarded as a joke. In addition to Newlands's octave periodic table of elements, there are actually Jean-Courtou Watts' spiral diagram and Meyer's six-element table. However, none of them can solve the problem of element arrangement well. Mendeleev's Periodic Table of Elements 1869 In March, based on a lot of work, Mendeleev published a paper entitled "The Relationship between Element Properties and Atomic Weight", put forward the periodic law of elements, and published his first periodic table of elements, covering 63 elements that had been discovered at that time. But there are 67 positions in the table, that is to say, there are four vacancies with atomic weight but no elements are found. This is Mendeleev's hypothesis of the existence of these four elements and his prediction of their properties. At the same time, he also questioned the atomic weights of indium, tellurium, gold and bismuth, and put forward the results that he thought were correct. With the further study of the periodic law of elements, he published his second periodic table in 187 1 65438+February. This table is more systematic than the first one. This periodic table of chemical elements was later recognized by the scientific community. Then why did Mendeleev succeed? This is mainly due to Mendeleev's persistent collection and mastery of massive elemental data, which lasted for nearly 20 years. And try to find patterns in massive data. He probably summed up three laws: periodic rise of elements is a universal law; The core characteristics of element periodicity are: gradual change; The change of some elements' characteristics is neither periodic nor the change range estimated by Mendeleev, so it is necessary to seek truth from facts at this time. How powerful is Mendeleev's periodic law? Let's give an example. At that time, a scientist discovered the element "gallium" and published his calculation results. Mendeleev wrote a letter to the scientist as soon as he saw it. The main idea of the letter is: the new element you found is just one of the four elements I predicted to exist. However, there is an oxide density data in your paper that is different from what I predicted. You must be wrong. At first, the scientist didn't take it seriously, but out of respect, he did it again, and the result was exactly the same as Mendeleev's prediction. This also became Mendeleev's famous battle, which suddenly caused a sensation throughout Europe. We know that Newton and Einstein are top physicists. They are great because they have completed a great theory by themselves, and more importantly, this theory can accurately predict. Mendeleev's position in chemistry is just like that of Newton and Einstein in physics. His periodic law of elements can not only sort the existing elements well, but also predict the existence of unknown elements. The "mistake" of the Nobel Prize is a pity in the field of chemistry. It stands to reason that Mendeleev has achieved so much that it is not a problem to win the Nobel Prize. In fact, he was nominated in 1904, 1905 and 1906 respectively. It is said that Mendeleev offended the Swiss chemist Arrhenius in his early years, and Mendeleev criticized Arrhenius' theory of dissolution. Arrhenius had a great influence on the judges of the Nobel Prize Organizing Committee, so under his influence, he didn't award the prize to Mendeleev. 1906, Mendeleev met a particularly powerful opponent, that is, the French chemist Movasan. His achievement is the production of elemental fluorine. The preparation of elemental fluorine is a bloody battle in the history of chemistry. Many years later, many chemists finally succeeded. In addition to producing elemental fluorine, Movado also prepared diamonds at that time, which is one of the reasons why he won the most awards. Therefore, in 1906, the Nobel Committee awarded the Nobel Prize to Movasan, mainly based on his contribution to the preparation of elemental fluorine. However, in his acceptance speech, Movasan talked about his preparation for diamonds, because he also felt that his award was mainly related to the preparation of diamonds. But he didn't know that in fact, his method could not make diamonds, but his students were tired of his stubbornness, so they secretly put diamonds into the experiment, which made Movado think that he was really successful. The matter finally came to light. Fortunately, the Nobel Committee at that time was conservative and did not write the reason for winning the prize as "preparing diamonds", otherwise it would be a big scandal in the history of the Nobel Prize. But it also made Mendeleev miss the last chance to win the prize. 1907 February, Mendeleev died of myocardial infarction. Later, whenever people talked about the "wrong prize" of the Nobel Prize, it was easy to think of Mendeleev. It is inconceivable that he didn't win the Nobel Prize in chemistry, just as Einstein didn't win the Nobel Prize in physics. Although Mendeleev is dead, his periodic law of elements will last forever with the development of human civilization. For the whole chemical community, this periodic table of elements is like a secret book of Wulin people. If you don't know, you are embarrassed to go out and tell others that you are a chemist. The essence of the periodic law of chemical elements actually reveals the internal relationship of matter. Later, the great physicist Pauli will reinterpret the essence of the periodic law of elements from the physicist's point of view. We'll talk more about it later.