Ernest Rutherford his work presentation. Presentation on the theme "ernest rutherford"

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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

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Ernest Rutherford

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Ernest Rutherford

Born into the family of wheel master James Rutherford and his wife, teacher Martha Thompson. Besides Ernest, the family had 6 more sons and 5 daughters.

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One of Rutherford's first discoveries was that the radioactive radiation from uranium consists of two different components, which the scientist called alpha and beta rays. Later, he demonstrated the nature of each component (they consist of fast-moving particles) and showed that there is still
and the third component which
called gamma rays.

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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!

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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
object to it
approval.

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• Ernest Rutherford is considered the greatest experimental physicist of the twentieth century. He is the central figure in our knowledge of radioactivity, as well as the man who laid the foundation for nuclear physics. In addition to its enormous theoretical significance, its discoveries have received a wide range of applications, including: nuclear weapons, nuclear power plants, radioactive calculations and radiation research. The impact of Rutherford's writings on the world is enormous. It continues to grow and is likely to increase further in the future.

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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

Ernest Rutherford

Completed by: Vasilyeva Lera

Grade 9 student

Ernest Rutherford is a British physicist of New Zealand origin.

Known as the "father" of nuclear physics. 1908 Nobel Prize Laureate in Chemistry. All of Rutherford's experiments were fundamental in nature and were distinguished by exceptional simplicity and clarity.

In 1911, with his famous experiment of scattering of α-particles, he proved the existence in atoms of a positive charged nucleus and negatively charged electrons around it. Based on the results of the experiment, he created a planetary model of the atom.

Biography

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, the son of a farmer who grew flax. 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. Graduated with honors from elementary school, earning 580 out of 600 points and a £ 50 bonus to continue his studies at Nelson College. Another scholarship allowed him to continue his studies at Canterbury College in Christchurch (now the University of New Zealand). In those days it was a small university with 150 students and only 7 professors. Rutherford is fond of science and begins research work from the first day.

Rutherford planned to study a radio wave or Hertz wave detector, take exams in physics and get a master's degree. But the following year, it turned out that the UK government post had allocated money to Marconi for the same job and refused to fund it at the Cavendish Laboratory. Since the scholarship was not even enough for food, Rutherford was forced to start working as a tutor and assistant for J.J. Thomson on the study of the process of ionization of gases under the influence of X-rays. Together with J.J. Thomson, Rutherford discovered the phenomenon of current saturation during gas ionization.

In 1898, Rutherford discovers alpha and beta rays. A year later, Paul Villard discovered gamma radiation (the name of this type of ionizing radiation, like the first two, was proposed by Rutherford).

In 1908, Rutherford was awarded the Nobel Prize in Chemistry "for his research in the field of the decay of elements in the chemistry of radioactive substances." In 1914, Rutherford was awarded a title of nobility and became "Sir Ernst". On February 12, at Buckingham Palace, the king ordained him a knight: he was dressed in a court uniform and girded with a sword. His heraldic coat of arms, approved in 1931, was crowned with the kiwi bird, the symbol of New Zealand, by the peer of England, Baron Rutherford Nelson (this was the name of the great physicist after elevation to the nobility). The coat of arms is an exponential representation of a curve characterizing the monotonic process of decreasing the number of radioactive atoms with time.

Ernest Rutherford coat of arms

Scientific activity

1904 - "Radioactivity".

1905 - "Radioactive transformations".

1930 - "Radiation of radioactive substances" (co-authored with J. Chadwick and C. Ellis).

Study of the phenomenon of radioactivity

After the discovery of radioactive elements, an active study of the physical nature of their radiation began. Rutherford was able to detect the complex composition of radioactive radiation.

The experience was as follows. The radioactive preparation was placed at the bottom of a narrow channel of a lead cylinder, and a photographic plate was placed opposite. The radiation leaving the channel was affected by a magnetic field. In this case, the entire installation was in a vacuum.

Diagram of an experiment for detecting a complex composition of radioactive radiation. 1 - radioactive preparation, 2 - lead cylinder, 3 - photographic plate.

Thus, it was found that with a charge equal to two elementary, an alpha particle has four atomic mass units. It follows from this that alpha radiation is a flux of helium nuclei.

In 1920, Rutherford suggested that there must be a particle with a mass equal to the mass of a proton, but without an electric charge - a neutron. However, he failed to find such a particle. Its existence was experimentally proven by James Chadwick in 1932.

In addition, Rutherford clarified the ratio of the electron charge to its mass by 30%.

Geiger - Marsden experiment with gold foil

Rutherford is one of the few Nobel laureates who has done his most famous work since receiving it. Together with Hans Geiger and Ernst Marsden in 1909, he conducted an experiment that demonstrated the existence of a nucleus in an atom. Rutherford asked Geiger and Marsden to look for alpha particles with very large deflection angles in this experiment, which was not expected from Thomson's atomic model at the time. Such deviations, although rare, were found, and the deviation probability turned out to be a smooth, albeit rapidly decreasing function of the deflection angle.

Rutherford was able to interpret the experimental data, which led him to develop a planetary model of the atom in 1911. According to this model, an atom consists of a very small, positively charged nucleus, which contains most of the mass of the atom, and light electrons orbiting it.

Scheme of the experiment on scattering of ɑ-particles. 1 - radioactive preparation, 2 - lead cylinder, 3 - foil from the material under study, 4 - semitransparent screen covered with ZnS, 5 - microscope.

Above: Expected results: α particles passing through the nucleus in the Thomson model. Bottom: Observed results: A small fraction of the particles deflected, indicating a small, concentrated positive charge. Note that the images are not to scale, and in reality the nucleus is much smaller than the electron shell.

Ernest Rutherford died on October 19, 1937, four days after urgent surgery for an unexpected illness - a strangulated hernia - at the age of 66 (although his parents lived to be 90). He was buried in Westminster Abbey, next to the tombs of Newton, Darwin and Faraday.

In honor of Ernest Rutherford are named:

chemical element number 104 in the periodic table - Rutherfordium, first synthesized in 1964 and given this name in 1997 (before that it was called "Kurchatoviy").

rutherford-Appleton Laboratory, one of the national laboratories of Great Britain, opened in 1957.

asteroid (1249) Rutherfordium.

Medal and Prize of the Rutherford Institute of Physics (Great Britain).

Sculpture of the young Ernest Rutherford. Memorial in New Zealand