The periodic table is one of the most iconic symbols of science. Over the years, it has evolved into the periodic table that we know today. Its history can be traced back to over 200 years ago. The Periodic Table has been altered, changed and redrawn into the modern Long Form Periodic Table.
The word periodic, comes as the periodic table contains elements following a periodic repetition of basic properties. The origins of the periodic table lie in a list of 33 known elements made by French scientist Antoine Lavoisier, Antoine Fourcroy, Louis-Bernard Guyton de Morveau and Claude-Louis Berthollet in 1787. In the earliest attempt to oraganise elements into fixed groups, German chemist Johann Döbereiner, in 1817, organised elements into groups of 3 called triads. He noticed that if the three members of a triad were ordered according to their atomic weights, the properties of the middle element fell in between those of the first and third elements. Also, Döbereiner showed that the atomic weight of the middle element is almost the average of the weights for the first and third members of the triad. Peter Kremers of Cologne also used the triad theory to suggest that certain elements could belong to two triads placed perpendicularly. He compared elements geometrically, a feature that later proved to be an important part of Mendeleev’s system.
In 1857 French chemist Jean-Baptiste- André Dumas turned away from the idea of triads and focused instead on devising a set of mathematical equations for increase in atomic weight among groups of chemically similar elements. But atomic weight is not the fundamental property of the elements, and so, he was not successful. English chemist John Newlands suggested in 1864 that when the elements were arranged in order of atomic weight, any one of the elements showed properties similar to those of the elements eight places ahead and eight places behind in the list- the Law of Octaves.
The first periodic table is said to have been drawn by Russian chemistry professor Dimitri Ivanovich Mendeleev and completed on the 17th February 1869. It included 63 elements in order of increasing atomic weight and also had spaces for elements proposed be undiscovered.
One of the most important features of the Mendeleev table was that it showed periodicity among elements, a feature that had been observed in 1862 by French geologist Alexandre- Emile Béguyer de Chancourtois. He positioned the elements according to increasing atomic weight along a spiral inscribed on the surface of a cylinder and inclined at 45 degrees from the base. The spiral started from oxygen and the first full round was completed at sulphur and so on.
Chemist Julius Lothar Meyer of Breslau University in Germany in 1868 produced a periodic table that turned out to be remarkably similar to Mendeleev’s famous 1869 version. But it did not come out until 1870 because of a publisher’s delay, a factor that contributed to a dispute that ensued between Lothar Meyer and Mendeleev. Had it not been for that publisher, we might have been reading Lothar Mayer’s name instead of Mendeleev’s (it’s easier to learn anyways!).
In 1894, William Ramsay of University College London and John William Strutt discovered the element argon over the next few years, Ramsay dicovered four other elements—helium, neon, krypton and xenon.In 1913 Dutch physicist Anton van den Broek suggested arrangement principle for the periodic table should be the nuclear charge of each atom. This fundamental quantity is now known as atomic number.
The modern periodic table has been designed in such a way that the position if elements directly corresponds with the position of electrons in the atomic electron shells. In 1924 physicist Wolfgang Pauli set out to explain the length of each row in the table. As a result, he developed the Pauli Exclusion Principle, which states that no two electrons can exist in exactly the same quantum state.
In the last 30 years too, researchers have tried to make alterations to the periodic table. Fernando Dufour has developed a three-dimensional periodic table, which displays the fundamental symmetry of the periodic law. In 1980 Ray Hefferlin devised a periodic system for all the diatomic molecules that could be formed between the first 118 elements. In a similar effort, Jerry R. Dias of the University of Missouri at Kansas City devised a periodic classification of a type of benzenoid aromatic hydrocarbons.
Still, the Periodic Table remains the most iconic chemistry symbols. After so much of evolution, we finally have perhaps the most perfect table ever.
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