In the early years, the strangest and often most accidental nature of chemistry was a discovery of the German brand Hennessy in 1675. Brand is convinced that human urine can extract gold. Similar colors seem to be a factor in his conclusion. He collected 50 barrels of human urine and stored it in the cellar for several months. Through various mysterious processes, he first turned urine into a toxic paste, and then turned the paste into a translucent wax. Of course, he didn't get gold, but a strange and interesting thing happened. After a while, it began to glow. And exposed to the air, it often spontaneously ignites.
It was soon called phosphorus, a name derived from Greek and Latin, which means "to shine". Foresighted industrialists have seen the potential commercial value of this substance, but it is difficult to produce and the cost is too high to develop. The retail price of an ounce (about 28.35g) of phosphorus is as high as 6 guineas-about 300 pounds today-in other words, it is more expensive than gold.
At first, people called on soldiers to provide raw materials, but this practice hardly helped industrial scale production. In 1950s, a Swedish chemist named Carl Kinler invented a method to produce phosphorus in large quantities without producing dirty and smelly urine. It is largely because of mastering this method of producing phosphorus that Sweden has become-and remains-a major producer of matches.
Kinle is not only an unusual person, but also an extremely unfortunate person. He is a junior pharmacist. He found eight elements-chlorine, fluorine, manganese, barium, molybdenum, tungsten, nitrogen and oxygen almost without advanced instruments, but he didn't get any honor. Every time, his findings were either ignored or published after others made the same discovery independently. He also found many useful compounds, including ammonia, glycerol and tannic acid; He also believes that chlorine can be used as a bleaching agent-the first person with potential commercial value-and these great achievements make others rich.
Kingler has one obvious shortcoming. He was curious about everything used in the experiment and insisted on tasting it, including some unpleasant toxic substances, such as mercury, hydrocyanic acid (which was also his discovery) and nitrile. Methonitrile is a famous toxic compound. 150 years later, Irving Schrodinger selected it as the best toxin in a famous thinking experiment. Kinler's reckless working method finally cost him his life. 1786, at the age of 43, he was found dead on the workbench, surrounded by toxic chemicals, any of which could cause the last stunned expression on his face.
If the world is just and everyone can speak Swedish, Jinle will enjoy a good reputation all over the world. In fact, people often praise more famous chemists, most of whom are chemists from English-speaking countries. Kinler discovered oxygen in 1772, but due to various bitter and complicated reasons, he failed to publish his paper in time. The credit goes to Joseph priestley, who independently discovered the same element, but later, in the summer of 1774. What's more noteworthy is that Kinler didn't get the credit for discovering chlorine. Almost all textbooks still attribute the discovery of chlorine to humphry davy. He did find out, but it was 36 years later than Kingler.
From Newton and Boyle to Kinle, priestley and Henry cavendish, there was a century between them. In this century, chemistry has made great progress, but there is still a long way to go. Until the last few years of the18th century (in the case of priestley, it was a little later), scientists all over the world were still looking for-and sometimes thought they really found-things that did not exist: deteriorated gas, marine acid without phlogiston, phlogiston, calcium oxide and lime, the smell of land and water, and especially phlogiston. At that time, phlogiston was considered as the motive force of combustion. They believe that there is a mysterious vitality in all this, that is, giving inanimate objects the power of life. No one knows where this elusive thing is, but two things are credible: first, you can activate it with electricity (mary shelley made full use of this understanding in her novel Frankenstein); Second, it exists in one substance but not in other substances. That's why chemistry is finally divided into two parts: organic matter (which means that there is such a thing) and inorganic matter (which means that there is no such thing).
At this time, an eagle-eyed person is needed to push chemistry to the modern age. There is such a person in France. His name is Antoine Laurent lavoisier. Lavoisier was born in 1743 and was a member of a small aristocratic family (his father paid a title for this family). 1768, he bought a start-up stock in an organization that was hated by people. That organization is called "tax company", which is responsible for collecting taxes and fees on behalf of the government. Everyone says that lavoisier himself is moderate and fair, but the company he works for has neither. On the one hand, only the poor are taxed, not the rich; On the other hand, it is often arbitrary. For lavoisier, this institution is very attractive, because it provides him with a lot of money to engage in his main work, that is, science. At the peak, his annual income was as high as150,000 livres-almost equivalent to today's120,000 pounds.
Three years after embarking on this lucrative career path, he married one of his boss's daughters, 14 years old. This is a marriage with a matching heart and brain. Mrs. lavoisier was clever and talented, and soon achieved a lot by her husband's side. Despite the pressure of work and busy social life, they spend five hours on most days-two hours in the morning and three hours in the evening-and the whole Sunday (they call it "Happy Day") engaged in scientific work. Somehow, lavoisier also managed to find time as a gunpowder commissioner, supervised the construction of a Paris wall to prevent smuggling, helped establish the metric system, and co-authored a manual called Chemical Nomenclature. This book became the "Bible" for unifying the names of elements.
As a major member of the Royal Academy of Sciences, no matter what is worth paying attention to at present, he still needs to know that he is actively involved in hypnosis research, prison reform, insect breathing, water supply in Paris and so on. 1870, a young and promising scientist submitted a paper to the academy of sciences, expounding a new combustion theory; It was at that post that lavoisier said a few contemptuous words. This theory is really wrong, but scientists have never forgiven him. His name is jean paul Mara.
There is only one thing that lavoisier didn't do, and that is to discover an element. In an era when anyone can discover new things with a beaker, a flame and any interesting powder-especially in an era when about two-thirds of the elements have not been discovered-lavoisier did not find an element. The reason, of course, is not the lack of beaker. It is almost absurd that he has the best private laboratory in the world. There are 13000 beakers in it.
Instead, he brought other people's discoveries and explained their significance. He abandoned phlogiston and harmful gases. He determined what oxygen and hydrogen are and gave them their present names. In short, he contributed to the rigor, clarity and order of chemistry.
His imagination is actually a breeze. For many years, he and Mrs. lavoisier have been busy with hard research, which requires the most complicated calculations. For example, they determined that rusted objects would not become lighter as people had long thought, but would become heavier-an amazing discovery. In the process of rusting, objects will attract the basic particles in the air in some way. For the first time, I realized that matter will only deform and will not disappear. If you burn this book now, its matter will turn into ashes and smoke, but the total amount of matter in the universe will not change. It was later called material immortality, which was a revolutionary idea. Unfortunately, it happened at the same time as another revolution-the French Revolution, and lavoisier was completely on the wrong side.
He was not only a member of the tax company, but also built the Paris wall with great energy-the uprising citizens hated this building so much that it was the first object of their attack. 179 1 year, Mara, who was already an important figure in the National Assembly, took advantage of this to condemn lavoisier and thought that he should have been hanged long ago. Soon, the tax company closed down. Soon after, Mara was killed by a persecuted young woman in the bath. Her name is Charlotte Cordé, but it's too late for lavoisier.
1793, the already tense "reign of terror" has reached a new height. In June 5438+10, Marie Antoinette was guillotined. 165438+ 10. In October, lavoisier and his wife were dragging their feet to make plans to escape to Scotland, and he was arrested. In May of the following year, he and 3 1 colleagues of the tax company were sent to the revolutionary court (in a court with a bust of Mara). Eight of them were acquitted, but lavoisier and several others were taken directly to Revolution Square (now Place de la Concorde), where the busiest guillotine in France was set up. Lavoisier watched his father-in-law's head fall to the ground, and then stepped forward to accept the same fate. Less than three months later, on July 27th, robespierre was sent to the west in the same way and in the same place. The reign of terror soon ended.
After his death 100, a statue of lavoisier was built in Paris, which was admired by many people until someone pointed out that it was nothing like him. Under questioning, the sculptor admitted that he used the head of mathematician and philosopher condorcet-he obviously prepared one-hoping that no one would notice, or even if he did, he wouldn't care. His latter idea is correct. Statues of lavoisier and condorcet were allowed to stay in place for another half century until the outbreak of World War II. One morning, someone took it away as scrap iron melted.
/kloc-at the beginning of the 0/9th century, nitrous oxide or nitrous oxide became popular in Britain, because people found that using this gas would "give people a high degree of pleasure and excitement". In the following half century, it became a high-grade drug used by young people. At one time, an academic group named asker Association stopped working on other things, but held a "Laughter Night", where volunteers could take a sip to boost their spirits and then amuse the audience with rickety funny gestures.
It was not until 1846 that someone found a practical method for nitrous oxide: using it as an anesthetic. Obviously, no one thought of it in the past, and God knows how many tens of thousands of people suffered unnecessary pain under the surgeon's scalpel.
I mention this point to show that chemistry, which developed in the18th century, lost its direction in the first decades of the19th century, just like geology in the first decades of the 20th century. Part of the reason is related to the limitations of instruments-for example, it was not until the end of that century that centrifuges appeared, which greatly limited a variety of experimental work. Part of the reason is society. Generally speaking, chemistry is a businessman's science, a person who deals with coal, potash and dyes, not a gentleman. Gentlemen are usually interested in geology, natural history and physics. Compared with Britain, the situation in continental Europe is slightly different, but only a little. ) there is one thing that may explain the problem. The most important observation of that century, namely Brownian motion, which determines the nature of molecular motion, was not made by chemists, but by Scottish botanist robert brown. (Brown noticed in 1827 that pollen particles suspended in water are always moving, no matter how long it lasts. The reason for this constant movement-the role of invisible molecules-has long been a mystery. )
If it weren't for an outstanding man named Count Lunford, the situation might be worse. Despite his noble title, he is an ordinary Benjamin Thompson native. 1753 was born in Woburn, Massachusetts, USA. Thompson is handsome, energetic, ambitious, and occasionally very brave, smart and unscrupulous. 19 years old, married a rich widow older than him 14 years old. However, when the revolution broke out in the colony, he foolishly sided with the royalists and once acted as a spy for them. In the disastrous 1776, he was in danger of being arrested on the charge of "not being enthusiastic about the cause of freedom". He was robbed in front of a group of anti-royalists, who wanted to dress him up with buckets of hot tar and bags of chicken feathers. He abandoned his wife and children and ran away in a hurry.
He fled to England first, and then came to Germany to serve as a military adviser to the Bavarian government. He deeply touched the authorities and was awarded the title of "Earl of Lunford in the Holy Roman Empire" in 179 1. During his stay in Munich, he also designed and prepared a famous park called English Garden.
During this period, he took time out to do a lot of pure scientific work. He became the most famous authority on thermodynamics in the world and the first person to explain the principles of liquid convection and ocean current circulation. He also invented several useful things, including a drip coffee pot, thermal underwear and a stove still called Renford stove. During his stay in France from 65438 to 0805, he pursued and married Madame lavoisier, the widow of Antoine Laurent lavoisier. The marriage was not successful, and they soon parted ways. Lunford stayed in France until his death in 18 14. Except for his ex-wives, he is universally respected by the French.
We mention him here because he founded the Royal Institute of Science during his short stay in London in 1799. At the end of 18 and the beginning of 19, many academic groups sprang up all over Britain and became another member. For a period of time, it was almost the only famous institution aiming at actively developing new chemical science, which was almost entirely attributed to an outstanding young man named humphry davy. Shortly after the establishment of this institution, David was appointed as a professor of chemistry in the institute, and soon became famous as an excellent lecturer and prolific experimenter.
Shortly after taking office, David began to announce the discovery of one new element after another: potassium, sodium, manganese, calcium, strontium and aluminum. He discovered so many elements, not so much because he discovered the arrangement of elements, but because he invented a clever technology: let the current pass through the molten substance-this is now called electrolysis. He always found the element 12, accounting for one-fifth of the total known in his time. David could have made greater achievements, but unfortunately, as a young man, he gradually became addicted to the relaxed and happy fun brought by nitrous oxide. He can't live without that gas. He has to inhale it three or four times a day. Finally, in 1829, it was thought that this gas killed him.
Fortunately, there are other serious people in other places who are engaged in this work. 1808, a young and tenacious Quaker named john dalton became the first person to announce the nature of atoms (we will discuss this progress more fully later); 18 1 1 year, an Italian with an opera-like beautiful name-Lorenzo Romano Madiot Carlo avogadro made a discovery that will prove to be of long-term significance-that is, any two gases with the same volume have the same number of atoms under the condition of equal pressure and temperature.
Later known as avogadro's law. This simple and interesting law is worth noting in two aspects. First of all, it lays the foundation for determining the size and weight of atoms more accurately. Chemists use avogadro number for final measurement. For example, the diameter of a typical atom is 0.0000000008 cm. This number is really small. Second, it has been almost 50 years, and almost no one knows about it.
On the one hand, it is because avogadro is a loner-he does research alone and never attends meetings; On the other hand, because there is no meeting to attend, few chemical magazines can publish articles. This is a very strange thing. The motive force of industrial revolution comes from the development of chemistry to a great extent, but chemistry has hardly existed independently as a systematic science for decades.
The London Chemical Society was not established until 184 1. It was not until 1848 that the Society published magazines regularly. By that time, most academic groups in Britain-Geological Society, Geographical Society, Zoological Society, Horticultural Society and Linnaeus Society (composed of naturalists and botanists)-had existed for at least 20 years, and some were much longer. Its rival Institute of Chemistry didn't come out until 1877, that is, one year after the American Chemical Society was founded. Due to the slow organization of the chemical industry, the news about the great discovery of avogadro in181did not spread until the first international chemical congress was held in Karlsruhe in 1860.
Because chemists have been working in an isolated environment for a long time, the speed of forming unified terms is very slow. Until the end of 19, H2O2 means water for one chemist and hydrogen peroxide for another chemist. C2H2 can refer to ethylene or biogas. Few molecular symbols are uniform everywhere.
Chemists also use all kinds of confusing symbols and abbreviations, which are often invented by themselves. J.J. Petraeus of Sweden invented a much-needed arrangement method, stipulating that elements should be abbreviated according to their Greek or Latin names. That's why the abbreviation of iron is Fe (from Latin ferrum) and the abbreviation of silver is Ag (from Latin argentum). Many other abbreviations are consistent with English names (nitrogen is n, oxygen is o, hydrogen is h, etc. ), which reflects the Latin branch nature of English, not because of its high status. In order to express the number of atoms in a molecule, Petraeus used a superscript method, such as H20. Later, for no particular reason, it became popular to change numbers to subscripts, such as H20.
Although it was sorted out occasionally, until the end of 19, chemistry was still in a state of chaos to some extent. Therefore, when an eccentric and untidy professor of St. Petersburg University in Russia rose to a prominent position, everyone felt very happy. The name of the professor is Dmitri Ivanovich Mendeleev.
1834, Mendeleev was born in Tobolsk, western Siberia, Russia, into a well-educated and wealthy family. This family is too big, and it is not clear in the history books how many Mendeleev family members there are: some data say that there are 14 children, while others say that there are 17 children. However, anyway, everyone thinks Dmitry is the youngest one. The Mendeleev family is not always lucky. When Dmitry was very young, his father, the principal of a local primary school, was blind and his mother had to go out to work. She was undoubtedly an outstanding woman and finally became the manager of a very successful glass factory. Everything went smoothly until 1848, when a fire burned the factory to ashes and the family fell into poverty. Determined to educate her little son well, the strong Madame Mendeleev hitchhiked more than 6,000 kilometers (equivalent to the distance from London to Equatorial Guinea) to St. Petersburg and sent him to the Institute of Education. She was exhausted and died soon.
Mendeleev completed his studies conscientiously and finally worked in a local university. He is a competent but not excellent chemist there. He is famous for his unkempt hair and beard rather than his talent in the laboratory. His hair and beard are only trimmed once a year.
But in 1869, at the age of 35, he began to ponder the arrangement of elements. At that time, elements were usually arranged in two ways-either by atomic weight (using avogadro's law) or by ordinary properties (for example, whether they were metals or gases). Mendeleev's innovation is that he found that the two can be combined in one table.
In fact, Mendeleev's method was put forward by an English amateur chemist named John Newland three years ago, which is common in the scientific community. According to Newlands, if elements are arranged according to atomic weight, they seem to repeat certain features in turn every eight positions-in a sense, they are harmonious. Not very clever-because it is too early to do so-Newlands named it "the law of octaves" and compared this arrangement to octaves on a piano keyboard. There may be some truth in Newlands's statement, but this practice is considered completely absurd and has been laughed at by everyone. At the rally, some joking listeners sometimes ask him if he can play a short piece of music with his elements. Newlands was discouraged, stopped studying and soon disappeared.
Mendeleev took a slightly different approach, grouping every seven elements together, but using exactly the same premise. Suddenly I feel that this method seems to be excellent and the perspective is clear. Because those features are repeated periodically, this invention is called "periodic table".
It is said that Mendeleev got inspiration from the single card game in North America and patience from other places. In that card game, cards are arranged in rows according to color and columns according to points. Using a very similar concept, he called the horizontal row period and the vertical row family. Looking up and down, you can immediately see a group of relationships; Look around and see another set of relationships. Specifically, columns put together elements with similar attributes. So the position of copper is above silver, and the position of silver is above gold, because they all have the chemical affinity of metals; Helium, neon and argon are in the same row because they are all gases. (What determines the order of arrangement is actually their electronic valence. If you want to know the electronic price, you have to report to night school. At the same time, elements are arranged in rows according to the number of protons in their nuclei-called atomic numbers.
At present, let's take a look at the arrangement principle: hydrogen has only one proton, so its atomic number is 1, ranking first; Uranium has 92 protons, so it's almost the end. Its atomic number is 92. In this sense, as Philip Bauer pointed out, chemistry is actually just a matter of counting. By the way, don't mix atomic number with atomic weight. Atomic weight is the sum of the number of protons and neutrons of an element. )
There are many things that people don't know or understand. The most common element in the universe is hydrogen; However, in the next 30 years, the understanding of it will stop here. Helium is the second most abundant element, which was discovered only a year ago-no one thought of its existence before-even if it was discovered, it was not on the earth, but in the sun. It was discovered by a spectroscope during an eclipse of the sun, so it was named after the Greek sun god Helius. Helium was not separated until 1895. Even then, thanks to Mendeleev's invention, chemistry is now firmly established.
For most of us, the periodic table is a beautiful and abstract thing, but for chemists, it suddenly makes chemistry orderly and clear, and it cannot be overstated. "There is no doubt that the periodic table of chemical elements is the most beautiful and systematic chart invented by human beings." In his book Chemical Elements on Our Earth: History and Application, Robert E. krebs wrote-in fact, you can see similar comments in every chemical history.
Today, there are "about 120 known elements"-92 are naturally occurring and more than 20 are made in the laboratory. The actual figures are somewhat controversial. Synthetic heavy elements can only exist for a millionth of a second. Chemists sometimes disagree about whether they are actually measured. In Mendeleev's time, people only knew 63 elements. To some extent, he was clever because he realized that not all the elements were known at that time, and many elements had not been discovered. His periodic table accurately predicted that once new elements were discovered, they could take their place.
By the way, no one knows the maximum number of elements, although anything with an atomic weight exceeding 168 is considered as "pure speculation"; However, it is certain that all the elements found can be neatly incorporated into Mendeleev's great chart.
/kloc-the 0/9th century gave chemists the last important surprise. Started at 1896. In Paris, henry beck Rael accidentally left a bag of uranium salt on the photosensitive plate wrapped in a drawer. After a while, when he took out the photosensitive plate, he was surprised to find that uranium salt burned a mark on it, as if the photosensitive plate had been exposed. Uranium salts are releasing some kind of radiation.
Considering the importance of this discovery, becquerel did a strange thing: he handed it over to a graduate student for investigation. Fortunately, this student happened to be a new Polish immigrant named Marie Curie. In cooperation with her new husband Pierre, Curie found that some rocks released a lot of energy continuously, but the volume did not decrease and there was no measurable change. What she and her husband can't know-no one can know until Einstein explains it in the next century-is that rocks are extremely effective in converting mass into energy. Marie Curie called it "radiation". In the process of cooperation, the Curies also discovered two new elements-polonium and uranium. Polonium is named after her native Poland. 1903, the curies and becquerel won the Nobel Prize in physics. (19 1 1 year, Marie Curie won the Nobel Prize in chemistry; She is the only one who has won both the chemistry prize and the physics prize. )
At McGill University in Montreal, ernest rutherford, a young man born in New Zealand, became interested in new radioactive materials. Together with a colleague named Frederic Soddy, he found that there is huge energy in a very small amount of matter, and most of the earth's heat comes from the radioactive decay of this reserve. They also found that radioactive elements will decay into other elements-for example, if you have a uranium atom in your hand today, it will become a lead atom tomorrow. This is really extraordinary. This is pure alchemy; No one thought that such a thing would happen spontaneously in the past.
Rutherford has always been a pragmatist, and he was the first person to see the valuable practical value. He noticed that no matter what kind of radioactive material, half of it decays into other elements at the same time-the famous half-life-and this stable and reliable decay rate can be used as a kind of clock. As long as you calculate how much radiation a substance has now and how fast it decays, you can calculate its age. He tested a pitchblende-the main uranium ore-and found that it was 700 million years old-older than most people thought the earth was.
1In the spring of 904, Rutherford came to London and gave a lecture to the Royal Institute of Science, which was founded by Count Lunford with a history of only 150 years, although for those who rolled up their sleeves and prepared for a big fight in the late Victorian era, the era of wearing white powder and wigs seemed so far away. Rutherford will talk about his newly discovered transformation theory of radiation phenomenon; As part of the lecture, he took out pitchblende. Rutherford cleverly pointed out-because the elderly Kelvin was present, although not always awake-Kelvin himself once said that if some other heat source was found, his calculation results would be overturned. Rutherford discovered another heat source. Due to the radiation phenomenon, it can be calculated that the earth is probably-it goes without saying-much older than Kelvin's final calculation of 24 million years.
Kelvin's face lit up when he heard Rutherford's respectful statement, but he was actually indifferent. He refused to accept the revised figures. Until his death, he thought that his calculated age of the earth was the most insightful and important contribution to science-much more important than his achievements in thermodynamics.
Like most scientific revolutions, Rutherford's new discovery was not universally welcomed. John joly of Dublin argued in the 1930s that the age of the earth should not exceed 89 million years, and it remained unchanged until his death. Others began to worry that Rutherford was talking too long now. However, even using radioactive dating method, which is later called decay calculation method, it will take decades to reach the conclusion that the real age of the earth is about 65.438+0 billion years. Science is on the right track, but there is still a long way to go.
Kelvin died in 1907. Dmitri mendeleev also died that year. Like Kelvin, his many achievements will be immortal, but his later life is obviously not peaceful. As people grow older, Mendeleev becomes more and more