In the fall of 1910, Ernst Rutherford, overwhelmed by reflection, painfully tried to understand the internal structure of the atom. His experiments on the scattering of alpha particles by various substances convincingly proved - inside the atom there is a certain, previously unexplored, massive body. In 1912, Rutherford would call it the atomic nucleus. Thousands of questions swarmed in the scientist’s head. What charge does this unknown body have? How many electrons are necessary to ensure its weight?
In May 1911, Rutherford published an article on the structure of the atom, which was preceded by a very significant reservation that the stability of the atomic structure probably depends on the intricacies of the internal structure of the atom and the motion of charged particles, which are its important structural component. So the electronic configuration was born - the nuclear-electronic atomic model. This model was destined to play an invaluable role in nuclear physics.
The electronic configuration is the order of distribution of electrons in atomic orbits. Thanks to the inquiring mind and perseverance of Ernst Rutherford, who managed to defend his idea, science was enriched with new knowledge, the importance of which cannot be overestimated.
The electronic configuration of the atom is as follows. At the center of the whole structure is a nucleus consisting of a different number of neutrons and protons for each substance. What determines the positive charge of the nucleus. Around it, in the corresponding concentric orbits, electrons move - negatively charged elementary particles. These atomic orbits are also called shells. The outer orbit of an atom is called valence. And the number of electrons on it is valency.
Each electronic configuration of elements differs in the number of electrons contained in it. For example, an atom of the simplest substance in the Universe - hydrogen - contains only one single electron, an oxygen atom - eight, and the electronic configuration of iron has twenty-six electrons.
But the decisive value in the electronic model of an atom is not at all the number of electrons, but what keeps them together and makes the whole system function properly - the nucleus and its composition. It is the core that gives the substance individual qualities and characteristics. Electrons sometimes leave the atomic model, and then the atom acquires a positive charge (due to the charge of the nucleus). In this case, the substance does not change its properties. But if you change the composition of the nucleus, then it will be a completely different substance with different qualities. This is not easy to do, but still possible.
Since the electronic configuration is impossible without its main structural element - the atomic nucleus, it should be given special attention. It is this central element of the atomic model that forms the individual properties and characteristics of any chemical substance. Protons, which, in fact, give the nucleus a positive charge, are 1840 times heavier than any electron. But the proton charge force is equal to the analogous value of any electron. In a state of balance, the number of protons in an atom is equal to the number of electrons. In this case, the core is a carrier of zero charge.
Another major particle of an atomic nucleus is called a neutron. It is this element, which has no charge, that made possible a nuclear chain reaction. So overestimating the value of the neutron is simply impossible.