On December 31, 1898, the 19th day of November in the 24th year of Guangxu in the lunar calendar, the hall of Beijing Normal University opened. The first batch of students was originally planned to enroll 500 people, because of the failure of the Wuxu Reform, many people were silent, so the enrollment work was not smooth, according to the literature records of the next year or two, in fact, there were 27 students in the College, 151 middle school students, 17 primary school students, and 43 students in the attached classes, and only more than 230 students in the school, middle school, primary school, and attached courses. Not much more than the students of Chongshi Middle School. However, it is the first national university in modern China, and it is the predecessor of famous universities such as Peking University and Beijing Normal University.

On the opening day, Sun Yuanqi, as the first batch of teachers in the school, was fortunate to attend the ceremony with Xu Jingcheng, the chief teacher of Chinese, and Ding Yunliang, the chief teacher of Western languages. After that, the university hall did not start classes immediately, after all, the students selected by the provinces have not yet arrived, and the relevant preparations are still proceeding slowly. But these are not Sun Yuanqi's concerns. Sun Yuanqi gave Lao Tong a few dozen taels of silver and instructed him to prepare gifts for Rutherford and Thomas. The rest of the money is used to buy some food every day and deliver it. During this time, Sun Yuanqi has been hiding in the house to write manuscripts.

That day, Rutherford's suggestion really moved him, and after coming back and weighing it for a long time, he decided to write a simple booklet and give it to Rutherford to take to Canada to see if it could produce results. Because Rutherford plans to leave for McGill on January 6 in time for McGill's next semester. Therefore, Sun Yuanqi's time was a little tight, so he had to stay in the house every day to write manuscripts.

The name of the booklet has been prepared, "From the Atom and Atomic Structure to the Elements, the Periodic Table, Molecules and the Nature of Chemical Reactions". Although the name is related to chemistry, the core is actually atomic physics. In fact, in the late nineteenth and early twentieth centuries, physics and chemistry were not too separated, for example, Rutherford, a great physicist, won the Nobel Prize in Chemistry in 1908 for his research on radiochemistry. Another example is the Swedish genius Arrhenius, who proposed the theory of ionization, whether he should win the prize in physics or chemistry, which also caused disagreement among the Nobel Prize judges. He was nominated for the first Nobel Prize in 1901, but was ultimately defeated. In 1902, he rose to fame and was nominated for the Chemistry Prize, but was still unsuccessful. As the founder of physical chemistry, Arrhenius's theory of ionization plays an important role in both physics and chemistry. In desperation, the chemistry committee proposed to give him "half of the physics prize and half of the chemistry prize", and even proposed that "the issue of his award being postponed to the second year". In the end, the committee awarded him the Nobel Prize in Chemistry in 1903.

In 1869, the Russian scientist Dmitri Mendeleev discovered the periodic law and the periodic table, he arranged the 63 elements known at that time according to their atomic weight and arranged them in the form of a table, and put the elements with similar chemical properties in the same row, which is the prototype of the periodic table. In the process of arranging the periodic table, Mendeleev boldly pointed out that some of the recognized atomic weights of the time were inaccurate. For example, at that time the atomic weight of gold was recognized as 169.2, according to this, gold should be ranked in the list of elements before osmium, iridium, and platinum, because they were recognized as atomic weights of 198.6, 196.7, and 196.7, respectively, and Mendeleev firmly believed that gold should be ranked after these three elements, and the atomic weights should be redetermined. The retest results show 190.9 for osmium, 193.1 for iridium, 195.2 for platinum, and 197.2 for gold. Practice confirms Mendeleev's assertion and also proves the correctness of the periodic law.

In the periodic table compiled by Mendeleev, there are still a lot of spaces that should be filled by elements that have not yet been discovered. Mendeleev theoretically calculated the most important properties of these elements that had not yet been discovered, concluding that they were between those of neighboring elements. For example, in the two spaces between zinc and arsenic, he predicted the properties of the two unknown elements, which were aluminum-like and silicon-like, respectively. Just four years after his prediction, the French chemist Boua Brown used spectroscopic analysis to discover gallium from the menzinc mine. Experiments have shown that gallium is very similar to aluminum, which is the aluminum-like predicted by Mendeleev. The discovery of gallium is of great significance, which fully shows that the periodic law of elements is an objective law of nature; It provides a law to follow for the research of future elements, the exploration of new elements, and the search for new materials and new materials.

Mendeleev arranges the periodic table by atomic weight and places elements with similar chemical properties in the same column. These are arranged in terms of the physical properties (mass) and chemical properties (chemical properties) of the elements, and do not reveal the most essential differences between the elements. Sun Yuanqi's dissertation starts from this perspective.

The paper starts from the conclusion of Sun Yuanqi's first two papers, arguing that the atom is composed of a nucleus and an outer electron shell, because the electrons are negatively charged, so there should be other positively charged particles in the nucleus, which are very small, but have almost the mass of the entire atom; They are structurally very stable and possess almost constant positive charge number and mass; The number of positive charges in the nucleus determines what kind of element the atom belongs to, and the number of positive charges in the nucleus is also positively correlated with the mass of the nucleus, that is, the atomic weight.

Because Sun Yuanqi did not have experimental equipment around him, he had to "design" the experiment of the British physicist Mosellet in 1913: using cathode rays to hit metal to produce X-rays. It is believed that the experimental result "should" be that the greater the atomic number of the metal, the higher the frequency of X-rays. Therefore, it can be proved that the positive charge of the nucleus determines the chemical properties of the element, and that the atomic number is quantitatively equal to the positive charge carried by the nucleus, and then it is clear that the basis of the periodic law is not the atomic weight, but the atomic number.

This is the first part of the dissertation that mainly discusses the relationship between the nucleus and the elements.

In the second part of the paper, Sun Yuanqi began to discuss the electrons in the outer shell of the nucleus and their relationship with elemental compounds. These are mainly "plagiarized" from the research results of Niels Henrik David Bohr, another great figure in the field of physics.

Bohr (1885-1962) was a well-known Danish physicist from a well-to-do family. In 1903 he entered the Faculty of Mathematics and Natural Sciences at the University of Copenhagen. In 1906, while still a student, Bohr was awarded the Gold Medal of the Royal Danish Academy of Sciences for his work on the surface tension of water. He received his M.S. and Ph.D. degrees from the University of Copenhagen in 1909 and 1911 respectively with his dissertations on the theory of metal electronics. In 1911, he went to Cambridge University in England and studied at J· Under the guidance of J. Thomson, he conducted research with Rutherford. In 1913, he wrote three papers, "Atomic Structure and Molecular Structure" (1), (2), and (3), and proposed an atomic model of steady-state transitions, that is, the famous Bohr atomic theory. In 1922, he was awarded the Nobel Prize in Physics for his research on the structure of atoms and atomic radiation. Of course, Sun Yuanqi is not going to explain Bohr's discussion of the "transition hypothesis" of electrons in this pamphlet - because Planck has not yet put forward the energy quantum hypothesis, and perhaps this is the object of "plagiarism" in the next paper - he is only going to say something superficial, just like the description in the physics and chemistry textbooks of middle schools in the 21st century, only in this way can he attract the attention of scientists and science lovers all over the world.

In this part, the "stationary hypothesis" of the electron shell is mainly discussed: the number of electrons in the outer shell of the nucleus should correspond to the number of positive charges in the nucleus, but how are they arranged? "According to" Mendeleev's periodic table, it is possible to "suppose" that the first shell has a steady state of 2 electrons, the second shell is 8, the third shell is also 8, and the fourth and fifth shells are 18...... In order to reach a steady state, atoms lose or trap electrons. The magnitude of the ability to lose or trap electrons determines the chemical properties of the element. The so-called molecule is a compound formed by the atoms of several elements arranged in a certain way to reach a steady state. The essence of chemical reactions, which can also be deduced from this principle, is that different ions form more stable compounds. Subsequently, the chemical reaction equations and the valency of elements were discussed and summarized.

In 1883, Arrhenius began to develop the theory of ionization, which explained how elements in solution were electrolytically separated. In 1884, he applied for a doctorate with his dissertation "A Study of the Conductivity of Electrolytes", but after he read his dissertation, the professors were "furious" and could not tolerate such "absurd" or even "purely utopian" theories. After a "heated debate" with Clive, his thesis was graded 3 and needed to be defended again. Later, his ionization theory gradually became accepted by the academic community, but he only explained this phenomenon and did not know why it was so. In Sun Yuanqi's paper, the most fundamental explanation is given.

The content of the essay is very simple in the eyes of modern people, because it has been written into secondary school textbooks and is taken for granted. But for the scientific community at the end of the nineteenth century, it was no less than a bolt from the blue, and it definitely had a deafening effect.

When Sun Yuanqi wrote, his main focus was on how to express it clearly but reasonably, and how to express it in English. After writing it, I felt that it was not like a scientific paper, nor like science fiction, but more like a detective transcript. Even so, Sun Yuanqi already felt very satisfied.

By this time, Rutherford had packed his bags and was ready to board a passenger ship across the Pacific Ocean, first to San Francisco, then across the United States, and into Canada. Sun Yuanqi took a gift from Lao Tong, and when he opened it, he saw that it was porcelain, embroidery, black tea, etc., and he didn't know if such a gift was suitable. Lao Tong next to him was full of pride:

"Although this is the first time we have bought a gift for a foreign devil, I specially asked Lord Ding Weiliang Ding, these are all recommended by him, and I will do it for a while! Did you see the porcelain? The authentic Jingdezhen official kiln, all of them are exquisite, and they will definitely not lose our share of the Qing Dynasty! If the foreign devil takes it, maybe it will be regarded as an heirloom! Look at this black tea again, the best grade Qi Hong! ……”

Sun Yuanqi had no choice but to praise Lao Tong a few words, praising him for knowing the "native products" of the Qing Dynasty well.

On the morning of January 5, after washing up, I took my gifts and booklet and went straight to the U.S. Legation in Dongjiaomin Lane. The two gifts were still a lot of money, so I hired a big car. During these days, the soldiers of the two countries who came by the embassy were all familiar with each other, and they went in without embarrassment. The Conger family and Rutherford are there, but Thomas will go to the United States with Rutherford tomorrow and then return to Cambridge, and the Conger family is quite gloomy.

The porcelain was afraid of breaking, so Sun Yuanqi instructed the coachman to carefully remove the gifts. Foreigners have always had the custom of looking at gifts first, and Mr. Conger and Rutherford were no exception, watching them from the sidelines, saying "onderful" and "Great", and as for how much of it was sincere, I don't know.

When the gifts are finished, go to the living room and have coffee together. At this time, Sun Yuanqi took out the freshly baked booklet and handed it to Rutherford: "Your suggestion has motivated me to write it, and I hope you can give some suggestions and criticism." ”

Rutherford took it, looked at the cover first, turned his head sideways, and read softly: "From atoms and atomic structures to elements, the periodic table, molecules, and the nature of chemical reactions." ”

Rutherford laughed and said, "From the name, it's an esoteric and interesting book, isn't it?" ”

Sun Yuanqi shrugged: "It feels like it's somewhat similar to "One Thousand and One Nights" or something." ”

In fact, Sun Yuanqi himself didn't think about what to name the booklet, but the content was like this, so he had the title of the book. Papers in the Western scientific community often start from a very small angle, such as Einstein's epoch-making paper published in 1905, the first of which is called "An Enlightening Idea of the Generation and Transformation of Light".

The booklet has one hundred and forty pages, and there are also numerous arguments and illustrations. In the place where Sun Yuanqi seems to be very clear, he is also watching, and occasionally asks questions, and the two discuss together. An hour has passed, and they have not finished watching the first part. Sun Yuan saw that they were very focused, so he didn't bother anymore and politely said goodbye to them: "I'll come over tomorrow morning to see you off." If in doubt, discuss it at that time. ”

The next day, when Sun Yuanqi rushed to the U.S. Legation, the Conger family and Rutherford had already tied their luggage to the car, and when Rutherford saw Sun Yuanqi, he stretched out his arms and said loudly: "York, Congratulations!" ”

Early in the morning, what do you congratulate me? Sun Yuanqi was confused. On second thought, it must have been a pamphlet thing. In any case, it is not to be rude, and replied: "Thankyou!" ”

After the hug, Rutherford said that he had read the paper with Thomas yesterday and at least found the first part of the discussion on the periodic law "fascinating". If the experiment proves to be correct, it will change the current system of physics, chemistry and other natural sciences. Because it not only gives a new explanation to the periodic law of elements, but also further clarifies the essence of the periodic law, and puts the periodic law, a natural law, on a stricter and more scientific basis, which is "of epoch-making significance".

At this time, it was already the ninth day, and it was freezing outside. Sun Yuanqi was wrapped in a cotton robe, pulled cotton shoes, and wore a melon skin hat, standing in the cold wind to discuss physics with Rutherford and Thomas, and only then could he recall that he was a graduate student in physics. Occasionally looking at the ghosts patrolling around, the low, dilapidated houses in the distance, and the state-of-the-art physics of the late nineteenth century, it feels like transforming into the big beetle in Kafka's works.

The cold wind from Siberia froze Rutherford and Thomas stamped their feet. After talking for a while, seeing that the time was almost up, he hurriedly pulled Sun Yuanqi into the carriage, lowered the curtain, and went straight to the train station.

At the end of the Qing Dynasty, the Beijing Railway Station was at the front gate, which was not very far from the Beijing Railway Station in later generations. From Dongjiaomin Lane to the front door, it only takes half an hour. During this time, the three of them have been discussing the relationship between atomic structure and elements. This problem is well known in the twenty-first century. But at the moment, it is necessary to explain it in various ways.

Originally, Sun Yuanqi planned to send Rutherford on the train. In the 21st century, this is a completely standard of etiquette. When they arrived at the station, their own maid watched as Lifu carried his luggage onto the train. Then he saw the Congers and Rutherford walking into the car, and then sat down. Sun Yuanqi didn't know what was going on, so he had to follow up. Yes, but a station attendant stopped him.

Sun Yuanqi thought to himself: Oh, it seems that the Qing Kingdom is giving away, and it also has to buy platform tickets.

The station manager said: "This is a carriage for foreigners, and idlers are not allowed to enter." ”

In the new century, we have become accustomed to the set of "entering with vouchers and registering with outsiders", and we have also seen places where security guards or armed police stand in a circle at the door and do not allow people to enter or leave. At the moment, Sun Yuanqi was not too angry, looking at this station office, it was a Chinese, not very old, estimated to be less than thirty years old, yellow and white skin, with his hands on his sleeves, and his face was somewhat cold. He asked, "Who made this a rule?" ”

"You don't care about that!" The station staff looked like they were ignoring it.

At this time, Rutherford saw that Sun Yuanqi did not follow, and turned around, but saw him talking to a station attendant, and the station attendant looked impatient. Although I don't understand Chinese, I can roughly guess a seven, eight, nine. At that moment, he stretched out his hand and pulled Sun Yuanqi and walked inside.

When the station saw that the foreigner pulled Sun Yuanqi in, he hurriedly stretched out his hand, as if he wanted to hold Sun Yuanqi, or prevent the foreigner from pulling, and opened his mouth wide, "Huh-......". But after all, he didn't speak, and his outstretched hand hung down.

Sun Yuanqi thought to himself: Is this a foreigner looking down on us, or are we looking down on ourselves? But Sun Yuanqi was reluctant to say Chinese in front of foreigners, so he had to make up a reason and said: "I haven't bought a ticket yet......

"Buy a ticket?" Rutherford asked suspiciously, "Conger knew you were coming to see us off, and he had already bought everyone's tickets." ”

"Already bought?"

"Yes, you send us to the sky together...... Tianjin's. Rutherford said.

"Go to Tianjin......" Sun Yuanqi was speechless, touched dozens of big money in his arms, and thought, I had to wait and trouble Mr. Conger.

Rutherford didn't notice Sun Yuanqi's abnormality, and continued: "Where did we talk about just now? Ha – by the way, when it comes to the nucleus of an atom it should be made up of several kinds of particles, one of which is positively charged, and one is neutral, but the mass is very large, almost the vast majority of the weight of the atom. These weren't written in your paper, so why weren't they? Did you just think of that? Is it a reasoning, a hypothesis, or a conjecture? ”

“……”

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