After it was discovered that a substance composed of molecules, and those in turn - of atoms, to the physicist got a new question.It was necessary to establish the structure of atoms - what does it consist.For solving this challenge came from Rutherford and his students.Opening the proton and the neutron they held at the beginning of the last century
Do Rutherford has been speculation as to what the atom consists of a nucleus and orbiting it at high speed electrons.But what constitutes the nucleus of the atom, it was not entirely clear.Rutherford suggested the hypothesis that the composition of the atomic nuclei of any chemical element to be the core of a hydrogen atom.
This hypothesis was later proved by a series of experiments, which resulted in the discovery was made of a proton.The essence of the experimental trials Rutherford was that nitrogen atoms are bombarded alpha radiation, through which some particles are knocked out of the atomic nuclei of nitrogen.
This process was recorded on a photosensitive film.However, the glow was so weak, and the sensitivity of the film was also small, so Rutherford proposed his disciples before proceeding to experience several hours to be in a dark room, so that the eyes could see subtle lights.
In this experiment, the characteristic light footsteps, it was determined that the particles that have been knocked out, are the nuclei of hydrogen and oxygen atoms.The hypothesis of Rutherford, which led him to the fact that the discovery was made of a proton, found its brilliant confirmation.
This particle Rutherford offered to call a proton (translated from the Greek "protos" means first).It should be understood so that the atomic hydrogen nucleus has a structure such that it has only one proton.Since the opening has been made of the proton.
electric charge it has a positive.At the same time it is quantitatively equal to the electron charge, but has the opposite sign.That is, it turns out that the proton and electron as it balance each other.Therefore, all of the items as they are composed of atoms that initially charged, and electric charge are obtained when they begin to act in an electric field.In the structure of atomic nuclei of various chemical elements may be increasing the number of protons in the atomic nucleus than hydrogen.
After the discovery was made of a proton, scientists began to realize that the nucleus of an atom of a chemical element does not consist of the proton as conducting physical experiments with the atomic nuclei of beryllium, we found that the mass of protons in the nucleus is composed of four units,While the overall mass of the nucleus - nine units.It was logical to assume that five more mass units owned by some unknown particles with no electric charge, since otherwise the electron-proton balance would be violated.
James Chadwick, a student of Rutherford, conducted experiments and was able to detect elementary particles that flew out of the atomic nucleus beryllium when bombarded their alpha radiation.It turned out that they have no electrical charge.It was detected lack of charge due to the fact that these particles do not respond to the electromagnetic field.Then it became clear that found the missing piece of the structure of the atomic nucleus.
this open D. Chadwick particle called a neutron.It turned out that it has the same mass as the proton, but, as has been said, it has no electric charge.
Furthermore, it was experimentally confirmed that the number of protons and neutrons is equal to the ordinal number of the chemical element in the periodic system.
in the universe can be observed objects such as neutron stars, which are often the final stage of stellar evolution.Such neutron stars have a very high density.
