(6.1.1)--16.ernestrutherford-fatherofnucl.pdf

《(6.1.1)--16.ernestrutherford-fatherofnucl.pdf》由会员分享，可在线阅读，更多相关《(6.1.1)--16.ernestrutherford-fatherofnucl.pdf（20页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、Ernest Rutherford-Father of Nuclear Physics 欧内斯特欧内斯特 卢瑟福卢瑟福-原子核物理学原子核物理学之之父父 When it comes to nuclear physics,do you think its very profound?You may wonder,what is the connection between nuclear physics and chemistry?In 1911,Ernest Rutherford proposed a nuclear structure model based on the experimen

2、tal phenomena of alpha particle scattering,which was rated as one of the most beautiful experiments in physics.His research on radioactivity has established that radioactivity is a change from the inside of atoms,and has done pioneering work in opening up a new scientific field,atomic physics.Ernest

3、 Rutherford won the Nobel Prize in Chemistry in 1908,for his investigations into the disintegration of the elements,and the chemistry of radioactive substances.He was born in New Zealand.And he worked for Victoria University,Manchester,United Kingdom,when he obtained the Noble Prize.PART ONE Biograp

4、hy The discovery of radioactivity in 1896 led to a series of deeper investigations.Rutherford demonstrated that there were at least two distinct types of radiation:alpha radiation and beta radiation.He discovered that radioactive preparations gave rise to the formation of gases.Working with Prof.Sod

5、dy,Rutherford advanced the hypothesis that helium gas could be formed from radioactive substances.In 1902 they formulated a revolutionary theory:that elements could disintegrate and be transformed into other elements.In 1895,as the first research student at the University of Cambridges Cavendish Lab

6、oratory in London,Rutherford identified a simpler and more viable methods of detecting radio waves than had been previously established by German physicist Heinrich Hertz.PART TWO Achievement Also,while at Cavendish Laboratory,Rutherford was invited by Professor J.J.Thomson to collaborate on a study

7、 of X-rays that was discovered just months before he arrived.By the way,J.J.Thomson received the Nobel Prize for Physics in 1906.Together,Rutherford and Thomson studied the effects of X-rays on the conductivity of gases,resulting in a paper about dividing atoms and molecules into ions.While Thomson

8、went on to examine electrons,Rutherford took a closer look at ion-producing radiations.Focusing on uranium,Rutherford discovered that placing it near foil resulted in one type of radiation being easily soaked up or blocked,while a different type of radiation had no trouble for passing through the sa

9、me foil.He labeled the two radiation types“alpha”and“beta.”As it turns out,the alpha particle was identical to the nucleus of a helium atom.The beta particle was,in fact,the same as an electron or positron.Rutherford overturned Thomsons model in 1911 with his famous gold-foil experiment,in which he

10、demonstrated that the atom has a tiny,massive nucleus.Five years earlier Rutherford had noticed that alpha particles beamed through a hole onto a photographic plate would make a sharp-edged picture,while alpha particles beamed through a sheet of mica only 20 micrometres(or about 0.002 cm)thick would

11、 make an impression with blurry edges.For some particles the blurring corresponded to a two-degree deflection.PART THREE Rutherfords nuclear model Remembering those results,Rutherford had his postdoctoral fellow and an undergraduate student refine the experiment.The young physicists beamed alpha par

12、ticles through gold foil and detected them as flashes of light or sparkles on a screen.The gold foil was only 0.4 m thick.Most of the alpha particles went straight through the foil,but some were deflected by the foil and hit a spot on a screen placed off to one side.They found that about one in 20,0

13、00 alpha particles had been deflected 45or more.Rutherford asked why so many alpha particles passed through the gold foil while a few were deflected so greatly.“It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper,and it came back to hit you,”Rutherford said later.M

14、any physicists distrusted the Rutherford atomic model because it was difficult to reconcile with the chemical behaviour of atoms.The model suggested that the charge on the nucleus was the most important characteristic of the atom,determining its structure.On the other hand,Mendeleyevs periodic table

15、 of the elements had been organized according to the atomic masses of the elements,implying that the mass was responsible for the structure and chemical behaviour of atoms.In general,Ernest Rutherford is the father of modern nuclear physics,and he is one of the most prominent names in the field of a

16、ll time.He is the first person to truly think of what nuclear physics could be,and he created an amazing resume that anyone would be happy with.He won the Nobel Prize in his field,and he widely considered the father of experimental and theoretical physics.The element,Rutherfordium,is named for Ruthe

17、rford while he was doing work on the atomic structure of each element.He was also able to determine that the atom he was working on were decaying.Scientists once believed that these atoms would not decay,but he used work by Madam Curie to further his own research.It was very easy for him to complete

18、,and he continued to make discoveries that showed that he was right in his thoughts.He was even so instrumental in the field that he has many things named after him.This is a very important part of the science of today,and people are still looking back at the experiments that he did because they wer

19、e so useful at the time.Rutherford also helped other people come up with their own theories,and he practically created the field that people are working in today.I think after todays lecture,you must have admired him as I do.Thanks for watching.思思 考考 卢瑟福从小家境贫寒，通过自己的刻苦努力，这个穷孩子完成了他的学业。这段艰苦求学的经历培养了卢瑟福一

20、种认准了目标就百折不回勇往直前的精神。后来学生为他起了一个外号鳄鱼鳄鱼，并把鳄鱼徽章装饰在他的实验室门口。因为鳄鱼从不回头，他张开吞食一切的大口，不断前进。1895年，在农场挖土豆的卢瑟福收到了英国剑桥大学发来的通知书，他接到通知书后扔掉挖土豆的锄头喊道：“这是我挖的最后一个土豆啦！”1908年，卢瑟福获得该年度的诺贝尔化学奖，他对自己不是获得物理学奖感到有些意外，他风趣地说：“我一个搞物理的怎么就得了个化学奖呢？”“这是我一生中绝妙的一次玩笑！”卢瑟福还是一位杰出的学科带头人，被誉为“从来没有树立过一个敌人，也从来没有失去一位朋友”的人。在他的助手和学生中，先后荣获诺贝尔奖的竟多达12人。1

21、922年度诺贝尔物理学奖的获得者玻尔曾深情地称卢瑟福是“我的第二个父亲”。科学界中，至今还传颂着许多卢瑟福精心培养学生的小故事。卢瑟福的实验室被后人称为“诺贝尔奖得主的幼儿园诺贝尔奖得主的幼儿园”。他的头像出现在新西兰货币的最大面值-100元上面，作为国家对他最崇高的敬意和纪念。The Experiments Continue Rutherford continued his work for many years after his Nobel Prize,and he continued searching to see how far into the atom that he coul

22、d look.Rutherford worked with every great name of the day.He did experiments with Neils Bohr who was looking at the way that electrons orbited an atom,and he worked with Hans Geiger on the radioactivity of many of the atoms he had done experiments.These names are known well today,but Rutherford was at the heart of all this work.He was a brilliant mind who was able to make it much easier for the world to understand how the building blocks of life are made.