Chemists generally refer to scientists engaged in modern chemical research, which can be divided into full-time and part-time. In the UK, they can also refer topharmacist。Chemistry is a natural science that studies the composition, structure, properties and change laws of substances at the atomic level, while chemists are workers specializing in these substances and their properties.Chemists willchemical element, atoms, molecules and how they interact.Chemists also study and test drugs, explosives and other things.Chemistry is a very important science, because most new drugs are developed through chemical technology.
The difference between a chemist and others is that they usually carefully check the changes of every object around them.Most of their work is to study how to mass produce all kinds of expensive pharmaceutical or industrial chemicals in order to benefit the public or make a profit.
Lavoisier, the father of modern chemistry
Every chemist has different specialties, but they have some common ways of doing things.First of all, when they look at something, they usually study whether it is an acid or a base, and analyze the object from an atomic perspective.Secondly, they carefully measured the proportion of different substances when the objects were mixed, the speed of reaction when the chemical action was in progress, and the difference of chemical properties between different objects.In addition, they will use their limited knowledge to try to understand things they are not familiar with, so that they can learn more knowledge.Material scientists areMetallurgyFamily, but they usually majored in chemistry when they were studying.
Most chemists go out to work when they graduate from college, but some companies employ people with doctorates.Many chemistry related jobs or college chemistry courses attach equal importance to mathematics, physics and chemistry, because chemistry is also known asCentral science。
At the time of master's degree, chemical science students have to specialize in a branch.Most people choose biochemistry,Organic chemistryOr inorganic chemistry, etc.
After reading the book, chemistry graduates become chemists and will come out to work.Most of them will joinchemical industryOr dopharmacist。In manyNational UniversityActually, there is one subjectPharmaceuticsJunior college, but some people will become pharmacists after finishing chemistry.Some chemists will choose to work for the government as technicians in government laboratories.
Mendeleev:Russiachemist.Born on February 7, 1834SiberiaToborsk, died on February 2, 1907St.Petersburg。In 1850, he entered Saint Petersburg Normal College to study chemistry, and in 1855, he became a teacher of Odessa Middle School after graduation.In 1857St. Petersburg University Associate professor.He went to Germany in 1859Heidelberg Universityfurther education.In 1860, he participated in the International Congress of Chemists held in Karlsruhe.In 1861, he returned to St. Petersburg to engage in scientific writing.In 1863, he was a professor of the Institute of Technology, and in 1865, he received a doctor's degree in chemistry.In 1866, he was professor of general chemistry at St. Petersburg University, and in 1867, he was director of the chemistry teaching and research section.Since 1893, he has been the Director of the Bureau of Weights and Measures.Elected in 1890Royal SocietyForeign members.
Character's Life
Mendeleev (ДмитрийИвановичМенделеев) was born on February 7, 1834SiberiaToborsk, died on February 2, 1907Petersburg。
In 1848, he joined the Petersburg Academy, and in 1850, he joined the Petersburg Normal University to study chemistry. In 1855, he obtainedTeacher qualification, and obtainedGold medalAfter graduation, he became a teacher of Odessa Middle School.
In 1856, he received an advanced degree in chemistry, and in 1857, he was appointed as an associate professor of the University of Petersburg.He went to Germany in 1859Heidelberg Universityfurther education.
In 1860, he participated in the International Congress of Chemists held in Karlsruhe.
In 1861, he returned to Petersburg to engage in scientific writing.Professor of the Institute of Technology in 1863, Mendeleev in 1864technical professional training schoolProfessor of chemistry, received a doctor's degree in chemistry in 1865.
In 1866, he was professor of general chemistry at Petersburg University, and in 1867, he was director of the chemistry teaching and research section.
Since 1893, he has been the Director of the Bureau of Weights and Measures.In 1890, he was elected as a foreign member of the Royal Society of England.
On February 2, 1907, the famous Russian chemist Mendeleev died at the age of 73.[2] In memory of this great scientist, in 1955U.S.AA. Gniorso, B.G. Harvey, G.R. Choppin, etc., bombarded the accelerator with helium nucleiEinsteinium(253Es), einsteinium combines with the helium nucleus to emit a neutron and obtain a new element, which is named after MendeleyevExtra（Mendelevium，Md）。
Major achievements
Mendeleev's greatest contribution is the discovery of the periodic law of chemical elements.It is now called Mendeleev's periodic law.In February 1869, Mendeleev compiled aperiodic table(Table 1).In March of the same year, he entrusted NA.MinshutkinAt the Russian Chemical Society, he read out a paper entitled "Relationship between the Attribute of Elements and Atomic Weight", and expoundedPeriodic law of elementsKey points of:
① As perAtomic weightThe elements arranged in the order of size show obvious periodicity in nature.
② The size of the atomic weight determines the characteristics of the element.
③ The discovery of many unknown elements should be expected, for example, elements similar to aluminum and silicon with atomic weights between 65 and 75 should be expected.
④ The atomic weight of certain elements can sometimes be modified after the same kind of elements are known.
In 1871, Mendeleev also published the paper "Periodic Dependence of Chemical Elements", which further elaborated the periodic law of chemical elements.He also revised the periodic table of chemical elements (Table 2)VerticalThe table of is changed to horizontal column, highlightingElement familyAnd periodicRegularity；DividedMain familyandAccessory family, making it basically modernperiodic table of ele mentsForm of.
In the process of discovering the periodic law and making the periodic table, Mendeleev ignored the recognized atomic weight at that timeRearrangementIn addition to the positions of some elements (Os, Ir, Pt, Au; Te, I; Ni, Co), and considering the reasonable positions in the periodic table, some other elements (InLa, Y, Er, Ce, Th, U), and predicted the existence of some elements.In the periodic table of elements in 1869, Mendeleev left four undiscovered elementsvacancy。In 1871, he also published a paper, "The Natural System of Elements and the Use of It to Indicate the Properties of Some Elements". For some elements, for example,Aluminoid、Boron likeThe existence and properties of silicon like compounds and their atomic weights are predicted in detail.There are 6 such vacancies left.Mendeleev's inference was confirmed by later chemical experiments.
The discovery of the periodic law of elements has inspired people to discover new elements and researchinorganic chemistryThe upsurge of theory.The discovery of the periodic law of elements is an important milestone in the history of chemical development. It systematizes a large amount of knowledge about various elements for hundreds of years, forms a unified system with internal links, and then makes it a theory.
Mendeleev also studied the relationship between the volume of gas and liquid and temperature and pressurecritical temperatureAnd proposed liquidthermal expansionOfEmpirical。In 1865, he studied the properties of the solution and proposedhydrateThe theory laid the foundation for the modern solution theory.From 1872 to 1882, he and his students accurately measured theCompressibility factor。
Mendeleev was awarded the Royal Society of England for discovering the periodic lawDavid Medal。He also won the award ofCopley Medal 。In 1955, scientists named element 101 asExtra。Mendeleev wrotePrinciples of ChemistryA book that has been translated into English, French and other languages.
Madame Curie
Madame Curie
Madame CurieMarie Curie (1867-1934) FrenchpolandScientistRadioactive phenomenon, found radium and poloniumradioactive element, twice in his lifeNobel Prize。As an outstanding scientist, Madame Curie has a social influence that ordinary scientists do not have.Especially because she is the pioneer of successful women, her example has inspired many people.A lot of peopleChildhoodI heard her story but got a simplified and incomplete impression.The world's understanding of Madame Curie.To a large extent, it was influenced by Madame Curie, the biography of the second daughter published in 1937.This book beautifies Madame Curie's life and deals with all the twists and turns in her life.American biographer Susan Quinn spent seven years collecting undisclosed diaries andbiographical information 。She published a new book: Maria Curie: A Life, which depicts a more detailed and in-depth picture of her hard, bitter and struggling life.
If you only look at your resume, it's easy to think that Maria Curie is just a successful scientist.She was in Poland in November 1867Warsawbirth.There are one brother and three sisters. Both parents are teachers.At the age of 15, she graduated from high school with the first place.After that, I worked for several yearsprivate tutor, came to the corporation in 1891ParisUniversity SorbonneBranch schoolsSorbonne received college education and graduated in 1894 with two certificates in mathematics and physics.In 1895, she worked withPierre Curie (Pierre Curie) married, and the eldest daughter Ir è ne was born in the autumn of 1897.Previously.She worked with Gabriel Lippman of SorbonnemagnetismResearch, and published the first paper;At this time, in order toDoctoral DissertationAs a preparation, she began to carry out new projects in Pierre's laboratory, and Pierre soon joined his wife's work.Their experimental notes began on December 6, 1897, and recorded the first observation of newradioactivityelementPolonium(pollonium).After several months of tracking and analysis, they officially submitted on July 18French Academy of SciencesIn the report read out, two important discoveries were made: one was the element polonium, and the other was the concept of radioactivity.The discovery of such phenomena as the purification of polonium and the separation of radium, another new element, has greatly stimulated chemical research;The study of radioactivity is a breakthrough in the study of the nature of matter.In June 1903, Madame Curie was awarded Physics after her thesis defenseDoctor of Science。In early November, the Curies were awarded the David Medal of the Royal Society（HumphreyDavyMedal); in the middle of November, it was learned that he and HenriBecquerel had won the same prizeThe nobel prize in physicsThis is the highest honor in recognition of their research on radioactive phenomena.In 1905, they got their second daughter Eve.Pierre died in 1906.In 1911, Madame Curie wonNobel Prize in Chemistry。For her discovery of polonium and radium.Madame Curie died in 1934.In 1935, her eldest daughter Ellen and her son-in-law, Fr é d é ric Joliot Curie, won the Nobel Prize in Chemistry (Madame Curie knew their scientific discoveries when she was alive).Madame Curie, published by the second daughter in 1937, became a popular biography all over the world.
Major achievements
Madame Curie is hereexperimental study A measuring instrument is designed, which can not only detect whether there is ray in a certain substance, but also measure the intensity of ray.After repeated experiments, she found that the intensity of uranium rays is proportional to the uranium content in the material, but has nothing to do with the state of uranium existence and external conditions.
Madame Curie is rightchemical elementAfter a comprehensive inspection of all compounds, an important discovery was made: an element called thorium can also automatically emit invisible rays, which shows that the phenomenon that an element can emit rays is not only the characteristic of uranium, but the common characteristic of some elements.She called this phenomenonradioactivity, call elements with this propertyradioactive element。The radiation they emit is called“Radiation”。
At the end of 1902, Madame Curie refined one tenth of the gram of extremely pureRadium chlorideAnd accurately measured its atomic weight.Since then, the existence of radium has been confirmed.Radium is extremely difficult to obtainNatural radioactive materialIts shape is shiny, likerefined saltThe same white crystal, radium has slightly blue fluorescence, which is beautifulLight blueThe fluorescence, into a woman's beautiful life and indomitable faith.stayspectral analysisWhich is associated with theSpectral lineAre different.Radium is not the first radioactive element discovered by human beings, but it is the most radioactive element.With its strong radioactivity, it can be further identifiedRadiationMany new properties of.So that many elements can be further applied in practice.Medical research has found that radium rays have different effects on different cells and tissues, and those cells that reproduce quickly are quickly destroyed by radium irradiation.This discovery made radium a curecancerA powerful means.Cancerous tumorIt is composed of cells that reproduce abnormally fast. Radium rays can destroy it much more than the surrounding healthy tissues.This new method of treatment developed rapidly in countries around the world.stayFrench RepublicRadium therapy is called Curie therapy.The discovery of radium fundamentally changed the basic principles of physicsscientific theoryIts development and application in practice are of great significance.
Pasteur
Pasteur
PasteurHe was born in the town of Dole in eastern France in 1822.He went to university in Paris, majoring in natural science.His talent did not show up when he was a student. One of his professors rated his chemistry score as "pass".But Pasteur obtained his doctor's degree in 1847, which soon proved that the professor's judgment was too early. Pasteur, only 26 years old, was due to his mirror image of tartaric acidIsomerAnd leapt into the ranks of famous chemists.
Major achievements
Pasteur is not the first person to put forward the theory of disease bacteria. Similar hypotheses have been put forward by Giroramo Ferrarcastoro, Frederick Henry and others before.But Pasteur strongly supported the theory of bacteria through a large number of experiments and demonstrations, which is the main factor that makes the scientific community believe that the theory is correct.
If the disease is caused by bacteria, it seems logical to avoid the epidemic disease by preventing harmful bacteria from entering the human body.Therefore, Pasteur emphasized the importance of bacteria prevention methods in clinical medicineSurgeryClinicalJoseph Lister Has a significant impact.
Harmful bacteria can enter the human body through food and drinks.Pasteur invented a method to eliminate microorganisms in beverages (called Pasteur's disinfection method). This method almost destroys contaminated milk where it is usedInfectious agentCompletely eliminated.
Pasteur was over 50 years old and began to studyanthrax-- A serious infectious disease that attacks cattle and many other animals, including humans.Pasteur proved that a special bacterium is the pathogenic factor of this disease.But more important than that, he invented a weak strainBacillus anthracisThe injection of this weak strain into cattle will make the disease attack mild without fatal danger, and will also make cattle immune to the normal condition of the disease.Pasteur's public demonstration proved that his method would make cattle immune, which caused a great sensation.People soon realized that his general method could be applied to many otherPrevention of infectious diseases。
Pasteur himself invented a human body based on his unparalleled achievementsImmunologyThis method can make people feel terriblerabiesImmune.Since then, other scientists have also invented ways to prevent and cure many serious diseases such asEpidemic typhusandpoliomyelitisVaccine.
Pasteur is an exceptionally diligent scientific worker.There are still many valuable small achievements on his merit book.It was his experiments, not those of others, that convincingly proved that microorganisms were not naturally produced.Pasteur also discovered the phenomenon of anaerobic life, that is, certain microorganisms can live in the absence of air or oxygen.Pasteur YesSilkworm diseaseThe research results ofcommercial value 。One of his other achievements was his inventionfowl cholera-- PoultryCholera vaccine。Pasteur died near Paris in 1895.
People often associate Pasteur with inventionSmallpox vaccineBritish doctorsEdward JennerCompare.Although Jenna's work is 80 years earlier than Pasteur's, I think Jenna is far less important than Pasteur's because his immune method is only effective for one disease, while Pasteur's method can and has been used for the prevention of many diseases.
Since the middle of the nineteenth century, the life expectancy of the population in many parts of the world has roughly doubled.In the whole human history, this huge increase in human life may have a greater impact on personal life than any other invention.actuallymodern scienceAnd medicine really gives the second life to everyone we live.If this extension of life can be fully attributed to Pasteur's work, I will not hesitate to list him at the top of this book.Pasteur's contribution is so important that in the last centurymortalityThe greatest achievement of the decline should undoubtedly be attributed to him.So he wasThis volumeTo be among the best.Pasteur has carried out a number of exploratory research throughout his life and has made significant achievements. He is one of the most accomplished scientists in the 19th century.He spent his whole life proving threescientific problems : (1) EachFermentationBecause of the development of micro bacteria, the French chemist found that heating can killBeerAn annoying microbe that becomes bitter.Soon“Pasteurization”It is applied to various foods and drinks.(2) Every infectious disease is the development of a microbe in the organism: due to the discovery and eradication of an invasionSilkworm eggsPasteur saved the French silk industry.(3) Microbacteria of infectious diseases can be alleviated under special cultivationvirulenceAnd turn them from germs to disease prevention vaccines.He realized that many diseases were caused by microorganisms, so he established the theory of bacteria.
Linus Carl Pauling (Linus CPauling, 1901.2.28-1994.8.19), is a famous quantum chemist in the United States.He is full of personality andcreative spirit, continue to developMarginal disciplineHe has made great achievements in many fields of chemistry and is the greatest chemist in the 20th century.Twice wonNobel Prize(1954Chemistry Award, 1962 Peace Prize), has a high international reputation.So far, he is the only scientist in the world who has won the Nobel Prize twice alone.
