teacher of physics and chemistry in schools is well known that a lot easier to explain a topic, if you resort to analogies or use approximate examples, explaining the "fingers".Although given description may not fully meet the standard model, however, this approach yields results.That is the case in atomic physics.
chemical properties of materials is relatively easy to explain if we use the theory of atomic structure, proposed in 1911 by the English physicist E. Rutherford.Despite the fact that his model is correct only in part, that is enough for the understanding of the processes.Today we will talk about what is the valence electrons, and what is their relationship with the properties of the material being studied.But first, let us remember the planetary model of atomic structure.
Rutherford determined that the atom is not indivisible particles, as previously thought, and consists of a heavy nucleus in the center and electrons orbiting around it.The electric charge of nuclei positive (+) and the electrons in turn, negative (-).Eight years after the publication of his theory of the atom, Rutherford was able to spend a unique, at the time, the experience - convert nitrogen into oxygen.Experience is "bombed" by alpha particles nitrogen atoms.Formed after the collision of oxygen and "extra" particle with a positive charge, later named the proton.
theory acquired finished form the core includes protons, using magnetic forces holding electrons in orbits.Since the atom is electrically neutral, and proton and electron attract each other, they are equal to the total amount.In 1932, physicist George. Chadwick found that in addition to protons in the nucleus are particles with no charge - neutrons.It is they who are responsible for the mass.Depending on the energy of the electron, it may be at different distances from the nucleus.The valence electrons - these are negatively charged particles that:
- are at a maximum distance from the nucleus to the outer orbits;
- can interact with neighboring atoms.
Under interaction is necessary to understand the opportunity to leave its atomic orbit or change the trajectory of motion.
valence electrons are defined very simply - on the periodic table.For the basic elements (except for the subgroups, as there are exceptions) true condition maximum number corresponds to the number of valence electrons of the group, which is an element of the study.Atoms having a large number of theoretical particle reluctantly gives them to other atoms, so is an oxidizing agent (picks up the missing).Conversely, when a small number of the group, the valence electrons are easily given to an element, entering into interaction.In this case, we are talking about reducing agent or donor atoms.
valence electrons are directly dependent on the state of the atom.So, if it in some way from the outside to provide additional energy (converted into an excited state), the valence orbits of the particles will be more.
data valence materials can actively use them, predicting outcome.For example, chemical sources of electric current through the electrolyte used elements that are able to send and receive email.Neutral material would in this case useless.It is not difficult to guess that if all the outer electron shell of an atom are filled, then the element is chemically neutral and does not react with other atoms (or the interaction force is so negligible that it can be ignored).A striking example of this - inert gases.
