it all began



Refuting an established history of that great discovery in chemistry was just a nightmare, I must say that many scientists before Mendeleev made attempts to create a chemical system.Fundamentals of its laid a German scientist I.Dobereiner, Frenchman Antoine de Chancourtois and some others.

himself DIMendeleev spent an incredible amount of experiments and spent about twenty years of his life in search of truth.They were formed by the basic values ​​and functions of the elements and their properties, only the information does not fit into something less structured.And when, after another sleepless night, he decided to rest for a couple of hours, the brain has issued what Mendeleev sought for so many years.

That is available to chemists in 1869 appe
ared the periodic table, and only in 1871 was formulated by the law itself, which is allowed to go not only chemistry, but also many other sciences forward.

essence of the law



Russian scientist Dmitri Mendeleev was first made a startling discovery of the fact that the atom - is not an end unit that it has a nucleus and orbiting protons and neutrons, that the main mass of the atom is concentrated inits core.It was derived rule change properties of naturally occurring elements and their compounds depending on the variation of the charge of the atomic nuclei.

The increase in nuclear charge occurs precisely at the transition from one chemical element to the second table in the neighborhood.It grows on one elementary charge charging unit, and this is reflected in the table below for each element identified by atomic number.This means that the number of protons in the nucleus, is numerically equal to the number of electrons that a neutral atom, which corresponds to the kernel.

This outer shell composed of electrons are determined by the properties of all chemical elements.These membranes can be changed only occasionally, and these changes are directly dependent on the increase or reduction of the charge of the nucleus, located in the atom, and it is this, not the atomic weight of elements is the basis of the periodic law.

Why is it important



Due to the periodic law became possible to predict the behavior of certain chemical elements in various reactions.It was also determined that there are no open science compound.Only a century later, the table was full.