Provincial chemistry teacher John Dalton in 1803 opened "The law of multiple proportions."This theory states that if a particular chemical element can form compounds with other elements, then every part of the mass of the weight will fall another matter, and the relationship between them will be the same as that between small integers.It was the first attempt to explain the complex structure of matter.In 1808, the same scholar, seeking to explain the discovery of the law, suggested that the atoms of different elements may have different masses.
first model of the atom was created in 1904.The electronic structure of the atom in this model, scientists called "plum pudding".It was thought that the atom - a body with a positive charge, wherein its constituents are mixed uniformly.Such a theory could not answer the question of whether the components of atoms in motion or at rest.Therefore, almost simultaneously with the theory of "pudding" Japanese Nagaoka proposed a theory in which the structure of the electron shell of an atom likened the solar system.However, referring to the fact that during the rotation of the atom around its components should lose energy, but this does not correspond to the laws of electrodynamics, Vin rejected planetary theory.
However, after the discovery of the electron, it became clear that the structure of the atom is more complex than it imagined.I have a question: what is an electron?How it works?Are there other subatomic particles?
the beginning of the twentieth century was finally adopted planetary theory.It became clear that each electron moving in its orbit the nucleus like planets around the sun, has its own path.
But further experiments and studies have refuted this opinion.It turned out that their own path the electrons are not, however, possible to predict the area in which the particle is most often.Revolving around the nucleus, electrons form orbital, called the electron shell.Now it was to investigate the structure of electron shells of atoms.Physicists are interested in questions: how electrons move?Is there a motion ordering?Perhaps the motion is chaotic?
Progenitor Bohr atomic physics, and a number of prominent scientists also proved that electrons revolve shell-layers and their movement corresponds to certain laws.We had to close and detailed study of the structure of electron shells of atoms.
especially important to know this building for chemistry because the properties of matter, it was already clear, depends on the device and the behavior of electrons.From this point of view, the behavior of the electron orbitals - the most important characteristic of this particle.It was found that the closer to the nucleus of the atom, electrons are located, the more effort must be applied to break the bond of the electron-nucleus.Electrons located near the nucleus have a maximum relationship with him, but the minimum amount of energy.At the outer electrons, on the contrary, the relationship with the core weakens and supply of energy increases.Thus, the electrons around the atom layers.The structure of the electron shells of atoms became clearer.It was found that the energy levels (layers) similar in form reserve energy of the particle.
Today we know that the energy level depends on n (this quantum number) and corresponds to an integer from 1 to 7. The structure of the electron shells of atoms and the greatest number of electrons in each level is determined by the formula N = 2n2.
more letters in this formula represents the highest number of electrons in each level, and the small - serial number of this level.
structure of the electron shell of atoms determines that the first shell can be no more than two atoms, and the fourth - not more than 32. Outside, a complete level contains no more than 8 electrons.The layers where the electrons less considered incomplete.
