Ernest Rutherford is a brilliant scientist who has made some truly great discoveries in chemistry and physics. What achievement turned physics on a new path of development? What particles did Rutherford discover? Learn the details of the biography and scientific activities of the researcher later in the article.
The beginning of life
Rutherford's biography begins with the small town of Spring Grove in New Zealand. There, in 1871, the future physicist and scientist was born in a family of immigrants. His father, a Scot by birth, was a woodworking master and had his own enterprise. From him, Rutherford acquired useful design skills for subsequent work.
The first successes were already in school, where he received a scholarship for college for excellent studies. Ernest Rutherford first studies at Nelson College, then enters Canterbury. With a wonderful memory and brilliant knowledge, he is noticeably different among other students.
Rutherford receives an award in mathematics, writes the first scientific work in physics, "Magnetization of Iron in High-Frequency Discharges." In connection with the work, he invents one of the first devices for the recognition of magnetic waves.
In 1895, physicist Rutherford argued with chemist Macloren for the possession of the Scholarship named after the World Exhibition. By coincidence, the opponent refuses the award, and Rutherford is given a good chance to conquer the scientific world. He leaves for England at the Cavendish Laboratory and becomes a Ph.D. under the supervision of Joseph Thomson.
Scientific works and achievements
Arriving in England, the student barely grabs the scholarship granted. He begins to look for a tutor. Rutherford's supervisor immediately noted his great potential, and was not mistaken. Thomson invited the young physicist to study the ionization of gas by x-rays. Together, scientists discovered that this causes the phenomenon of current saturation.
After successfully working with Thomson, he delves deeper into the study of Becquerel rays, which Maria Sklodowska-Curie would later call radioactive. At this time, he makes his first important discovery, revealing the existence of previously unknown particles, studying the properties of uranium and thorium.
He later becomes a professor at the University of Montreal. Together with Frederick Soddy, the scientist puts forward the idea of transforming elements in the process of decay. At the same time, Rutherford writes the scientific works Radioactivity and Radioactive Transformations, which bring him fame. He becomes a member of the Royal Community, is awarded the noble title.
For research on the decay of radioactive elements in 1908, Ernest Rutherford was awarded the Nobel Prize. The scientist discovered the emanation of thorium, the artificial transmutation of elements upon irradiation of nitrogen nuclei, wrote three volumes of works. One of his most important achievements is the creation of a model of the atomic nucleus.
What particles did Rutherford discover?
Rutherford was not the first in the study of radiation. Before him, the physicist Becquerel and the Curie spouses actively explored this area. The phenomenon of radioactivity was then discovered very recently, and energy was considered an external source. Studying carefully the uranium salts and their properties, Rutherford noted that the rays discovered by Becquerel are heterogeneous.
Rutherford's foil experiment showed that a radioactive beam is divided into several particle flows. Aluminum foil can absorb one stream, the other can pass through it. Each of them is a lot of small elements called scientist alpha and beta particles or rays. Two years later, the Frenchman Villard discovered the third kind of rays, which, following the example of Rutherford, he called gamma rays.
What particles Rutherford discovered had a huge impact on the development of nuclear physics. A breakthrough was made and it was proved that the energy comes from the uranium atoms themselves. Alpha particles were defined as positively charged helium atoms, beta particles were electrons. Gamma particles discovered later are electromagnetic radiation.
Radioactive decay
Rutherford's discovery gave impetus not only to physical science, but also to himself. He continues to study radioactivity at the University of Montreal in Canada. Together with the chemist Soddy, they conduct a series of experiments with which they note that the atom changes during the emission of its particles.
Like medieval alchemists, scientists convert uranium into lead, making another scientific breakthrough. So radioactive decay was discovered . The law according to which the decay occurs, Rutherfor and Soddy described in their works "Radioactive Transformation" and "A Comparative Study of the Radioactivity of Radium and Thorium."
Researchers determine the dependence of the decay intensity on the number of radioactive atoms in the sample, as well as on the elapsed time. It was noted that over time, the decay activity decreases exponentially. Each substance needs its own time. Based on the decay rate, Rutherford was able to formulate the principle of half-life.
Planetary Atom Model
At the beginning of the 20th century, many experiments were already conducted to study the nature of atoms and radioactivity. Rutherford and Villard discover alpha, beta, and gamma rays, and Joseph Thomson, in turn, discovers an electron. It measures the ratio of the charge to the mass of the electron and makes sure that the particle is part of the atom.
Based on his discovery, Thomson creates an atom model. The scientist believes that the latter has a spherical shape, over the entire surface of which are distributed positively charged particles. Inside the ball are negatively charged electrons.
A few years later, Rutherford refutes the theory of his teacher. He claims that an atom has a nucleus that is positively charged. And around it, like planets around the sun, electrons revolve under the influence of Coulomb forces.
Rutherford experience diagram
Rutherford was an outstanding experimenter. Therefore, doubting the Thomson model, he decided to refute it experimentally. The Thomson atom should have looked like a spherical cloud of electrons. Then alpha particles must pass freely through the foil.
For the experiment, Rutherford constructed the device from a lead box with a small hole in which radioactive material was located. The box absorbed alpha particles in all directions except where the hole was. This created a directed flow of particles. Ahead were several lead screens with slots to weed out particles deviating from a given course.
A clearly focused alpha beam that passed through all the obstacles was directed at a very thin sheet of gold foil. Behind her was a luminescent screen. Each contact of particles with it was recorded as a flash. So it was possible to judge the deviation of the particles after passing through the foil.
Surprisingly to Rutherford himself, many particles deflected at large angles, some even 180 degrees. This allowed the scientist to assume that the bulk of the atom is the dense substance inside it, which is subsequently called the nucleus.
Rutherford experience diagram:
Criticism of the model
Rutherford's nuclear model was initially criticized, because it was contrary to the laws of classical electrodynamics. While spinning, electrons must lose energy and emit electromagnetic waves, but this does not happen, which means they are at rest. In this case, the electrons should fall on the nucleus, and not rotate around it.
Dealing with this phenomenon fell Niels Bohr. He establishes that each electron has its own orbit. While the electron is on it, it does not radiate energy, but it has acceleration. The scientist introduces the concept of quanta - portions of energy that is released when electrons move to other orbits.
Thus, Niels Bohr became one of the founders of a new branch of science - quantum physics. The correctness of the Rutherford model has been proven. As a result, the concept of matter and its motion has completely changed. And the model is sometimes called the Bohr-Rutherford atom.
Interesting facts about the scientist
Ernest Rutherford received the Nobel Prize before he made the most important achievement of his life - he discovered the atomic nucleus and established a planetary model of the atom.
Rutherford's landmark discovery led to the emergence of a new industry that studies the structure of the atomic nucleus. It is called nuclear or nuclear physics.
The physicist possessed not only research, but also teaching talent. Twelve of his students were Nobel Prize winners in physics and chemistry. Among them are Frederick Soddy, Henry Mosley, Otto Gan and other famous personalities.
The scientist is often credited with the discovery of nitrogen, which is erroneous. Indeed, another Rutherford became famous for this. Gas was discovered by botanist and chemist Daniel Rutherford, who lived a century earlier than an outstanding physicist.
Conclusion
The British scientist Ernest Rutherford became famous among his colleagues for his craving for experiments. Throughout his life, the scientist conducted many experiments, thanks to which he was able to discover alpha and beta particles, formulate the law of decay and half-life, and develop a planetary model of the atom. Before him it was believed that energy is an external source. But after the scientific world found out what particles Rutherford discovered, physicists changed their minds. The achievements of the scientist helped to take huge steps in the development of physics and chemistry, and also contributed to the emergence of such an industry as nuclear physics.