The periodic law is the basis of the periodic table of elements. This law indicates that the chemical and physical properties of the elements tend to repeat themselves in a systematic way as the atomic number increases. The table, therefore, is a kind of scheme that is in charge of ordering the chemical elements according to the increasing order of the atomic numbers.
A British chemist named John Alexander Reina Newlands (1838–1898) was one of the precursors of this concept by proposing the law of octaves, which indicated that every eight elements are found similar properties. Under this idea, Newlands drew up a periodic table in 1863.
The German Chemist Julius Lothar Meyer (1830–1895) drew on these notions to discover the atomic volumes of the elements. After calculating the different atomic weights and making graphs with these values, this expert was able to show that the increase in atomic weight corresponded to an increase in physical properties. The works of Meyer regarding the periodic law were published in 1870.
The Russian chemist Dmitri Mendeleev (1834–1907), however, he is the one who has remained with the historical merit as creator of the periodic table of the elements. His work consisted of ordering the elements according to their atomic mass and placing those that had something in common in the same column. His table, presented in 1869, was based on manual alteration of chemical properties.
The vertical columns of the periodic table are known as groups and include elements with identical atomic valence (and that, therefore, have similar properties to each other). The horizontal rows, meanwhile, are called periods and they group elements with properties that are different but whose masses are similar.
This law empirical, whose authorship belongs to the British-born physicist Henry Moseley in 1913, defines that when an atom emits an X-ray there is a systematic relationship between its atomic number and wavelength.
The importance of this law is that it left behind the notion that the atomic number it was simply the representation of the place that each element had in the periodic table, which had been assigned almost without specific reason by Mendeleev.
Thereafter, Moseley undertook a number of experiments to confirm Bohr’s model of the atom (also proposed in 1913 by the Danish physicist Niels, who posits that electrons can orbit stably around the nucleus atomic, among other things of great importance) in X-ray energies, starting from the measurement of the frequencies that originate in the electronic transitions suffered by heavy atoms.
The table in the form of a periodic table
While the periodic table represents a nightmare for many high school students, it generates fascination beyond belief in others. This is the case of Theodore Gray, co-founder of Wolfram Research, one of the most respected software and innovation companies scientific and technique, who in 2002 built a table in the shape of a periodic table, which contains samples of each element located according to the distribution of Dmitri Mendeleev.
His work did not end there, but began to distribute different designs of his creation to museums and schools, with particular emphasis on the importance of appreciating the elements live and direct, as opposed to simply seeing their nomenclature on paper. Although this man does not have the fame of a popular singer, his active collaboration with science is widely recognized among people who like this branch of knowledge, and on the Internet there is a lot of information about him and his discoveries.