The structure of the atomic nucleus is one of the most important issues of modern science. The experiments constantly carried out in this field allowed scientists not only to determine with a high degree of accuracy what an atom is, but also to actively use the knowledge gained in various industries and to create the latest weapons.
The question of the structure of everything that exists on the planet has interested scientists since time immemorial. So, even in Ancient Greece, some scientists believed that matter was unified and indivisible in its structure, and their opponents insisted that matter was divisible and consist of the smallest particles - atoms, so the properties of various objects are so different from each other.
A breakthrough in the study of the structure of molecules occurred in the XVIII century, when in the works of M.V. Lomonosov, L. Lavoisier, D. Dalton, A. Avogadro laid the foundations of the atomic-molecular theory, according to which everything in nature consists of molecules, and those, in turn, are indivisible particles - atoms, the interaction of which with each other determines basic properties of certain substances.
A new stage in the study of the structure of molecules and atoms began at the end of the 19th century, when E. Rutherford and several other scientists made discoveries, as a result of which the structure of the atom and atomic nucleus appeared in a completely new light. So, it turned out that the atom is not at all an indivisible particle, on the contrary, it consists of even smaller components - the nucleus and electrons that move around it in intricate orbits. The general neutrality of the atom has led to the conclusion that electrons having a negative charge must be balanced by elements with a positive charge. As it turned out later, such elements really exist: they are called ɑ-particles, or protons.
Modern scientific knowledge suggests that the structure of the atomic nucleus is much more complex than it seemed even a hundred years ago. So, today it is known that the nucleus of an atom includes not only protons, but also particles that do not have a charge - neutrons. Together, protons with neutrons are called nucleons. Since the neutron mass is only 0.14% higher than the mass of the proton, this difference is usually neglected in calculations.
The size of the nucleus is between 10-12 and 10-13 cm. Moreover, despite the fact that more than 95% of the mass of the atom is concentrated in the nucleus, the size of the atom itself is one hundred thousand times the size of the nucleus.
The main quantitative characteristics that characterize the structure of the atomic nucleus can be extracted from the periodic table of D.I. Mendeleev. As you know, the number of protons in the nucleus is equal to the sum of the electrons rotating around it and corresponds to the serial number in the table of elements. In order to know the number of neutrons, it is necessary to subtract the serial number from the total mass of the element and round to an integer. Substances in which the number of protons coincides, and the number of neutrons is different, are called isotopes.
One of the most important questions asked by scientists who studied the structure of the nucleus was the question of the forces that hold protons, because, having the same charge, they must be repelled. Studies have shown that the distances between protons in the nucleus are so small that repulsion between them simply does not occur. Moreover, bions that are located between protons contribute to close interaction and constant attraction of the latter to each other.
The structure of the atomic nucleus is still fraught with many mysteries. Their solution will not only help mankind better know the structure of the world, but also make a qualitative breakthrough in science and technology.