modern concept of the atom, which is the confirmation of the works of more scientists, theorists and scientists of the twentieth century, allow us a high degree of probability to judge its structure and its composition in the presence of various elementary particles.The atomic nucleus is a central part of the massive atom.It is composed of protons and neutrons, collectively referred to - the nucleons.The bulk of the atom (99.95%) is concentrated in its nucleus.Its size is extremely small, and the electric charge of a positive and a multiple of the absolute charge of a single electron.
by the number of electrons, or charge of the atomic nucleus, it is possible to judge the individual properties of the element.This number corresponds to its ordinal number in the periodic system.
discovery of the atomic nucleus is a credit to Rutherford (E. Rutherford), his experiments in 1911 with a scattering of a-particles as they pass through matter have allowed a high degree of probability to describe the structure of the atom.
The basis was taken the atomic nucleus of hydrogen, and the elementary particles that make up the foundation of the nuclei of other chemical elements, received in 1920 the name of the proton.However, the proton-electron structure of the atom had a number of shortcomings and did not explain many physical phenomena.
The description of the composition of the core science of elementary particles came close after the discovery of the neutron.In 1932 Dzh.Chedvik (J. Chadwick), V. GŃ‘yzenberg (W. Heisenberg) and DD Ivanenko have suggested the presence of particles in the nucleus of a neutral charge.A building material, which consists of a nucleus are protons and neutrons.The number of nucleons determines the mass number of the element.
Substances with the same number of protons in the nucleus (nuclear charge) are called isotopes.IZOTON - substances which have the same number of neutrons.Substances with the same number of nucleons - isobars.
Nuclear physics requires a smaller component "building blocks" for neutrons and protons.Quarks, gluons, mesons field constitute a complex system - the atomic nucleus.Further description of the complex interrelationships of elementary particles takes on quantum chromodynamics.
Assuming the problem of stability of the nucleus, which is composed of particles with no electrical charge (neutrons) and positively charged protons, scientists have concluded that at the core there is a special action of the nuclear forces that differ from electromagnetic and fromgravity.
effect of these forces is strictly limited by distance, they are limited to short-range and small range.
to the charge of nucleons nuclear forces show a hefty independence.Equally attracted a completely different particle.This phenomenon is evident when comparing the binding energies of mirror nuclei.This term refers to the kernel with the same number of nucleons, only the number of protons in one corresponds to the number of neutrons in the other and vice versa.An example could be the nucleus of helium and tritium (heavy hydrogen).
also unusual phenomena occur during the formation of nuclei.If we calculate the mass of the nucleus and the mass of separate elements of its constituent, the mass of the nucleus will be less.This effect is due to release in the synthesis of the core energy, which is called the binding energy of the atomic nuclei.Numerically it can be determined by calculating the amount of work that is required to make a nuclear fission in the constituent elements (nucleons) without reporting them to a certain kinetic energy.
In this regard, we introduced the concept of the specific energy of the nucleus.It is calculated as a numerical equivalent per nucleon, an average of 8 MeV / nucleon.With the increase in the number of nucleons in the nucleus occurs decrease the binding energy.
As a criterion for the stability of atomic nuclei using the ratio of the number of protons and neutrons.
