History knows such cases where great ideas come scientist accidentally.This can be attributed to the French physicist Henri Becquerel, carried out in 1896 the discovery of radioactivity.The reason for conducting the experiments was to study W. Roentgen X-rays.This scientist has made the assumption that they are linked to the phenomenon of luminescence.And the likelihood that this type of illumination is not possible without the cathode rays.
Becquerel decided to study the hypothesis put forward by W. Roentgen.He wondered whether the glowing substance beaming, having the ability to penetrate opaque walls.To answer this question, Becquerel took a photographic plate wrapped her black film, put salt uranium coated copper cross and placed in the sun.After some time, he showed the film.It turned out that it was black in those places where there was cross.This indicated that the uranium is capable of generating radiation passing through opaque objects and actions on a photographic plate.At the time, Becquerel believed that the reason for the emission of uranium - the sun.
After some time, the scientist decided to repeat the experiment.But this time overcast rainy weather prevented him to begin research.Becquerel put down the plate in black with a cross wrapped in a dark closet for several days.When the film showed a physicist, it turned out that being in the dark, it was black a lot more than when exposed to the sun.Exploring a large number of chemical compounds, Becquerel found that emit rays that penetrate through the dark paper, capable of only substances in the composition of which there is uranium.This was done by the discovery of radioactivity
Subsequently, this phenomenon has been thoroughly studied, and his wife Maria Sklodowska Pierre Curie.The discovery of radioactivity was the reason for the study of many other elements.Pierre and Marie discovered that many chemicals can emit rays of the three inputs: beta, alpha, gamma.They have carefully studied the phenomenon of radioactivity, studied his penetrating ability and behavior in a magnetic field.These discoveries have allowed scientists to find a lot of speed and charge of the particles that make up light.
The studies were made important discoveries in the field of physics.It was found that the alpha rays are myriad of relatively heavy particles, the velocity of which 16 thousand km per second.Each of them has two positive charges of electricity and has a mass.At the heart of the beta radiation - electrons, or negatively charged light elements.Their speed reaches more than 300 thousand kilometers per second.A gamma rays in its composition similar to the X-ray.A little later, physicists have found a few interesting facts.It turned out that emit alpha or beta particles, atoms of one chemical elements can be transformed into the other.
The study of ores, which included a thorium and uranium, has been opened a brand new, not previously studied chemical element.Its name - complete - it was in honor of Mary's home country - Poland.A little later, physicists discovered another radioactive element - radium (radiant).This component is allocated fairly strong radiation.In the table D. Mendeleev radium has an atomic weight of 226, took 88 cell.A little later, it was determined that the chemical elements, the sequence number is greater than 83, by their nature are radioactive, that is able to spontaneously generate radiation.
In 1903, the Curies for the discovery of radioactivity were awarded the Nobel Prize.Marie Curie became the first woman professor.Thanks to her Sorbonne University for the first time introduced a course on the study of radioactivity.
