degree of oxidation - a conditional element in charge of the atom molecule.This concept is fundamental to inorganic chemistry, without understanding it is impossible to imagine the processes of oxidation-reduction reactions, types of bonds in molecules, the chemical and physical properties of the elements.In order to understand what is the degree of oxidation, you first need to understand what makes up the atom itself and how it behaves when interacting with their peers.
It is known that the atom consists of protons, neutrons and electrons.Protons and electrons, also called nucleons, form a positively charged nucleus, around revolve negative electrons.The positive charge of the nucleus is balanced overall negative charge of the electrons.Therefore, the atom is neutral.
Each electron has a certain energy level, which determines the location of its proximity to the core: the closer to the core - the less energy.They are arranged in layers.Electrons have a single layer of almost the same amount of energy and form an energy level or the electronic layer.The electrons in the outer energy level is not too strongly bound to the nucleus, so they can participate in chemical reactions.Elements having externally from one to four electrons in chemical reactions usually give up electrons and those having five or seven electrons - accepted.
There are also chemical elements called inert gases, in which the outer energy level contains eight electrons - the maximum possible amount.They practically do not enter into chemical reactions.So, any atom tends to "supplement" their outer electron layer to the required eight electrons.Where to get the missing?In other atoms.In the course of a chemical reaction element with greater electronegativity "takes" an electron from an element with a lower electronegativity.Electronegativity of chemical elements depends on the number of electrons in the valence level and the strength of their attraction to the nucleus.An element, electrons are taken away, the overall negative charge is greater than the positive charge of the nucleus, and have given up electrons - on the contrary.For example, a compound of sulfur oxide SO oxygen having a high electronegativity, takes from two sulfur electrons and acquires a negative charge, while the sulfur remained without two electrons receives a positive charge.In this case, the degree of oxidation of oxygen is the oxidation state of sulfur, taken with the opposite sign.The oxidation state is written in the top right corner of the chemical element.In our example, it looks like this: S + 2O-2.
The above example is fairly simplistic.In fact, the outer electrons of one atom is never completely transferred to the other, they become a "common", therefore, the degree of oxidation of the elements is always smaller than designated in textbooks.
But to simplify the understanding of the chemical processes that fact neglected.
