Download presentation ernest rutherford. Presentation on Ernest Rutherford
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But Rutherford found that some of the alpha particles deflected very strongly when passing through the gold foil. In fact, some even fly backwards! Sensing that there was something important behind this, the scientist carefully counted the number of particles that flew in each direction. Then, through a complex but completely convincing mathematical analysis, he showed the only way that could explain the results of the experiments: the gold atom consisted almost entirely of empty space, and almost all atomic mass was concentrated in the center, in a small "nucleus" of the atom! But Rutherford found that some of the alpha particles deflected very strongly when passing through the gold foil. In fact, some even fly backwards! Sensing that there was something important behind this, the scientist carefully counted the number of particles that flew in each direction. Then, through a complex, but completely convincing mathematical analysis, he showed the only way that could explain the results of the experiments: the gold atom consisted almost entirely of empty space, and almost all atomic mass was concentrated in the center, in a small "nucleus" of the atom!
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Rutherford's personality constantly amazed everyone who met him. He was a large man with a loud voice, boundless energy and a noticeable lack of modesty. When colleagues noted Rutherford's supernatural ability to always be "on the crest of the wave" of scientific research, he immediately replied: "Why not? After all, it was I who caused the wave, right?" Few scientists would become Rutherford's personality constantly amazed everyone who met him. He was a large man with a loud voice, boundless energy and a noticeable lack of modesty. When colleagues noted Rutherford's supernatural ability to always be "on the crest of the wave" of scientific research, he immediately replied: "Why not? After all, it was I who caused the wave, right?" Few scholars would object to this claim.
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In 1911, Rutherford experimentally tested Thomson's model of the atom. Passing a beam of α-particles through a thin gold foil, Ernest Rutherford found that some of the particles are deflected at a fairly significant angle from their original direction, and a small fraction of α-particles are reflected from the foil. But according to Thomson's model of the atom, these α-particles, when interacting with foil atoms, should be deflected at small angles, of the order of 2˚. The results of the experiment surprised Rutherford so much that he exclaimed: "... as implausible as if you fired a fifteen-pound projectile into the tissue paper, and the shell would bounce back and kill you." Rutherford showed that Thomson's model was in contradiction with his experiments. Rutherford's main experiment
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E. Rutherford was born on 30.08. 1871 in New Zealand, in a large family; He studied excellently at Canterbury College of the Humanities, University of New Zealand; 1892 - received a Bachelor of Arts degree; 1894 - received a bachelor's degree in natural sciences; 1895 - Master of Arts, the best passing exams in mathematics and physics .; 1895 - as the best student sent to England to the Cavendish Laboratory of Cambridge under the leadership of J. Thompson; Stages of life - the "father" of nuclear physics E. Rutherford Library in Cambridge
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Rutherford was born in New Zealand in the small village of Spring Grove, located in the north of the South Island near the city of Nelson, to the family of a flax farmer. Father - James Rutherford, immigrated from Perth (Scotland). Mother - Martha Thompson, originally from Hornchurch, Essex, England. At this time, other Scots emigrated to Quebec, Canada, but the Rutherford family was unlucky and the government provided a free steamer ticket to New Zealand, not Canada. Ernest was the fourth child in a family of twelve. He had an amazing memory, good health and strength. Sculpture of the young Ernest Rutherford. Memorial in New Zealand Biography
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Rutherford's main experiment Bombardment of a thin plate of gold with α-particles K - lead container with a radioactive substance, E - screen covered with zinc sulfide, F - gold foil, M - microscope 1-gold atom 2-α-particles
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Model of the atom At the center of the atom, like the Sun in the Solar System, is the core, in which, despite its relatively small size, the entire mass of the atom is concentrated. And around it, like planets moving around the Sun, electrons revolve.
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Colleagues and disciples of E. Rutherford In his work and life, E. Rutherford met with many scientists, physicists, chemists, future Nobel Prize winners: Joseph John Thomson Peter Leonidovich Kapitsa Maria Sklodowska-Curie Henry Moseley James Chadwick Enrico Fermi
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Public Recognition 1914 - Received a title of nobility and becomes "Sir Ernst" 1923 - President of the British Association 1925 - President of the Royal Society 1931 - Title of Baron, Lord Rutherford of Nelson 1931 - Peerage 1933 - President of the Academic Council to Aid Those Who Fled from Germany
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Rutherford's personality constantly amazed everyone who met him. He was a large man with a loud voice, boundless energy and a noticeable lack of modesty. When colleagues noted Rutherford's supernatural ability to always be "on the crest of the wave" of scientific research, he immediately replied: "Why not? After all, it was I who caused the wave, right?" Few scholars would object to this claim. Rutherford's personality
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Interesting facts For his kind disposition, the students nicknamed Rutherford the Crocodile. In 1931, Crocodile procured 15 thousand pounds sterling for the construction and equipment of a special laboratory building for Kapitsa. In February 1933, the laboratory was inaugurated in Cambridge. On the end wall of a 2-storey building, a huge crocodile was carved into stone. It was commissioned by Kapitsa by the famous sculptor Eric Gill. Rutherford himself explained that it was him. The front door was opened with a gilded crocodile key. E. Rutherford, who discovered the atomic nucleus, spoke negatively about the prospects of nuclear power: “Everyone who hopes that the transformation of atomic nuclei will become a source of energy is nonsense.” When Peter Kapitsa came to work in Cambridge to Rutherford, he told him that the laboratory staff had already completed. Then Kapitsa asked: - What permissible error do you allow in experiments? - Usually about 3% - How many people work in the laboratory? - 30 - Then 1 person is about 3% of 30 Rutherford laughed and accepted Kapitsa as a "permissible mistake." After receiving the news in 1908 that he had been awarded the Nobel Prize in Chemistry, Rutherford said: “All science is either physics or stamp collecting.” Ernest Rutherford’s great-grandson, Michael Rutherford, -rock to Genesis and his band Mike & the Mechanics.
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List of Internet resources http://ru.wikipedia.org/wiki/%C0%F2%EE%EC http://www.edu.delfa.net/Interest/biography/biblio.htm http://textik.ru/ citations / topic / nauka /? fiz.1september.ru ›2006/21 / 12.htm http://class-izika.narod.ru/9_35.htm http://fizika.ayp.ru/9/9_1.html http: //www.newreferat .com / ref-12715-1.html
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Ernest Rutherford
Born in New Zealand. The son of a cattle farmer. From 1895 he worked at the Cavendish Laboratory. He was the first "overseas doctoral student".
Participated in the work on the study of cathode and X-rays under the leadership of J.J. Thomson. Developed a "magnetic detector of electromagnetic waves".
Since 1898 he began to study radioactivity. Established the charge and mass of the particles. He proved (together with F. Soddy) that an atom of another element appears in the process of radioactive decay. Established the law of radioactive decay.
In 1898 - 1907 worked in Montreal (Canada), in 1907 - 1919. - at the University of Manchester (UK). 1919 - 1937 - Director of the Cavendish Laboratory.
Particle Research
Scattering of α-particles by a mica plate
1909, Rutherford, Marsden, Geiger.
It has been found that one of about 8000 particles is scattered at an angle close to 180 °.
Hans Geiger
Scattering particles by gold foil
Rutherford wrote: "It is as incredible as if you fired a 15-inch projectile into a piece of tissue paper and the projectile returned to you and struck."
Scattering particles by gold foil
The probability of such a "reversal" of a particle is much less than 1/8000. It is practically zero.
Scattering particles by gold foil
The only one
a plausible explanation for the large-angle scattering of -particles was the presence of a massive, albeit very small, positively charged body inside the atom.
At the end of 1910, Rutherford told Geiger: “I know how
looks like an atom. "
At the very beginning of the article in "Phylosophical Magazine" it is written: "It is too early to consider the question of the stability of the atom."
And yet they turn?
The reasons why the planetary atom cannot exist:
- electrons move along closed trajectories, therefore, they move with acceleration;
- charged particles moving with acceleration must emit EME and therefore lose energy, and hence speed;
- as a result, the electron must fall onto the nucleus.
6.4. The rule
bohr - Sommerfeld quantization.
What do atoms and quanta have in common?
Niels Bohr (1885 - 1962)
1. In order to explain how the planetary atom of Rutherford can exist, Bohr put forward a bold assumption that the property of quantization, that is, discrete change, is inherent not only to quanta of light - photons, but has a deeper meaning.
2. He drew attention to the fact that Planck's constant h has a dimension (in the SI system, which did not exist at that time, J · s), which coincides with the dimension of a physical quantity called action.
3. Bohr suggested that all physical quantities should change so that in the course of any processes the action should be equal to an integer number of Planck's constants h.
4. Based on the assumption about the quantization (jump-like change) of the action, Bohr assumed that when an electron moves in an orbit around a positive charged nucleus, the condition
that is, the action of the electron is quantized.
Bohr - Sommerfeld quantization rule
According to Planck, the emission of light occurs in portions - quanta, energy
which is equal to h
E h.
The change in the energy of a standing wave arising in a cavity around a black body is also equal to E h h.
Standing waves can be thought of as linear harmonic oscillators. According to Planck, of all possible states of a linear harmonic oscillator, only those are realized whose energy is
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Ernest Rutherford (Rutherford Ernst) 08.30.1871-19.10.1937 English physicist, a native of New Zealand, the founder of nuclear physics, the author of the planetary model of the atom, a member (in 1925-30 President) of the Royal Society of London, a member of all the academies of sciences in the world, including (since 1925) a foreign member of the USSR Academy of Sciences, laureate of the Nobel Prize in Chemistry (1908), founder of a large scientific school. Research is devoted to radioactivity, atomic and nuclear physics. With his fundamental discoveries in these areas, he laid the foundations of the modern doctrine of radioactivity and the theory of the structure of the atom. Collection www.eduspb.com Collection www.eduspb.com
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At the Cavendish Laboratory From the www.eduspb.com collection From the www.eduspb.com collection
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Brief biography 1876 - 1888 - years of primary apprenticeship - school in Foxhill to Havelock. Nelson College for Boys. 1889 Ernest Rutherford enters Canterbury College, New Zealand University (Christchurch, South Island). - Bachelor of Arts degree. - Master of Arts degree. 1884 - Beginning of work on the creation of a magnetic detector of electromagnetic waves. 1895 - Bachelor of Science degree. 1851 World's Fair Fellowship: Rutherford enters the Cavendish Laboratory, Cambridge University, England. The first doctoral student (research-student) J.J. Thomson. 1896-1887 - Together with J.J. Thomson, Rutherford studies the process of ionization of gases under the influence of X-rays. Termination of work on the magnetic detector. 1898 - Rutherford's first steps in the study of radioactivity. Discovery of non-uniformity of Becquerel radiation - alpha and beta rays. Professor at McGill University in Montreal. 1899 - Thorium emanation is discovered. 1901 - 1902 - Joint research with Frederick Soddy. Discovered natural transformation of elements and the creation of the theory of radioactive decay of atoms. - Election as a member of the Royal Society of London. - The first book of Rutherford - "Radio activity". The first Bakerian lecture - "The sequence of transformations in radioactive families" From the collection www.eduspb.com From the collection www.eduspb.com
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1905 - The second book of Rutherford - "Radioactive Transformations" (a cycle of Silliman's lectures at Yale University, USA). 1906 - First experiments on the scattering of alpha particles in matter. 1907 - Moving to England. Beginning of professorship at the University of Victoria (Manchester). 1908 - Development together with Hans Geiger of the alpha-particle counting method. The final establishment, together with Thomas Royds, of the helium nature of alpha rays. Nobel Prize in Chemistry. 1909 - 1910 - Construction of a planetary model of the atom and the maturation of the idea of \u200b\u200bthe existence of an atomic nucleus. 1911 - Appearance in the "Philosophical magazine" of Rutherford's work - "Scattering of alpha and beta radiation in matter and the structure of the atom". 1912 - Start of friendship and cooperation with Niels Bohr. 1913 - Rutherford forwards Niels Bohr on the structure of atoms and molecules for publication. - Rutherford submits for publication Henry Moseley's High Frequency Spectra of Elements. 1914 - Rutherford receives the nobility and becomes Sir Ernst. 1915-1917 - Work on the detection of German submarines. Rutherford is the "liaison officer" of the British Invention and Research Committee. 1917 - The beginning of experiments, culminating in the discovery of the artificial transformation of elements. 1919 - Appearance in the Philosophical magazine of Rutherford's work - "Anomalous effect in nitrogen" (the fourth article in the series "Collision of alpha particles with light nuclei"). Discovery of artificial fission of the atomic nucleus. - Second Bakerian Lecture - "The Nuclear Structure of Atoms." Prediction of the possible existence of a neutron, deuterium, tritium and helium-3. Collection www.eduspb.com Collection www.eduspb.com
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1921 - The beginning of cooperation and friendship with P. L. Kapitsa. 1923 - President of the British Association, Congress in Liverpool. 1925 -1930 - President of the Royal Society. 1930 - The appearance of the third book of Rutherford, co-authored with J. Chadwick and C. Ellis - "Radiation of radioactive substances." 1931 - Rutherford receives the title of Baron and becomes Lord Rutherford of Nelson. 1932 - Rutherford introduces J. Cockcroft and E. Walton to the Royal Society, who carried out the first nuclear reaction with accelerated protons. At the same meeting, J. Chadwick reports on the discovery of the neutron. 1933 - Opening of the Le Monde Laboratory. - Rutherford - President of the Academic Council for Aid to Exiles from Hitler's Germany and other European countries. 1934 - Together with Marcus Oliphant and P. Hartek, Rutherford carries out the first nuclear reactions with heavy hydrogen. 1937 - Rutherford's last book is the popular Modern Alchemy. October 19 - Death of Rutherford. Collection www.eduspb.com Collection www.eduspb.com
"The structure of the atom" - Molecules. Henri Becquerel. Proved that the atom has a dense core. J. Joseph Thomson. William Crookes. Substance. Atoms. Ernest Rutherford. In 1879 he discovered cathode rays. The number of protons in an atom is equal to the ordinal number. Basic information about the structure of atoms. The charge of the nucleus coincides with the number of the chemical element in the periodic table.
"Atom in Physics" - Contents. When passing from orbit to orbit, the electron emits quanta. Bohr's postulates. Head: A. V. Sargsyan Second postulate. In a stationary state, the atom does not radiate. Rutherford is known as the "father" of nuclear physics, he created a planetary model of the atom. hv \u003d IEn-EmI. Based on the classical concepts of the motion of microparticles, Rutherford proposed a planetary model of the atom.
"The structure of the nucleus of an atom" - It is designated -, has a mass? 1a.m. and a charge equal to the charge of an electron. - Particles core. 10 -12. Glass screen covered with a special substance. A radioactive emitting substance - particles. 2 - 4. 17. Rutherford's model of the atom. The structure of the atom. Radioactive transformation of atomic nuclei. 16.13 - 15.
"Atomic nucleus" - The neutron is now known to be 0.1% heavier than the proton. Nuclear forces. Chadwick's experiments. However, inside a stable nucleus, neutrons are bound to protons and do not spontaneously decay. Kernel model. Discovery of the structure of the nucleus. J. Chadwick repeated the experiment. 1932 Ivanenko and Heisenberg proposed a proton-neutron model of the atomic nucleus.
"Application of the photo effect" - The use of vacuum photocells in sound films. Electronic textbook on physics. Exit work. The history of the discovery and research of the photoelectric effect. Difficulties of the wave theory in explaining the photoelectric effect. PRESENTATION