This was noticed early by people, and Greek thinkers, about 400 BC, used the words ‘element’, and ‘atom’ to describe the differences and smallest parts of matter. These ideas survived for 2000 years while Aristotle’s concepts, such as ‘elements’ of Earth, Fire, Air, and Water to explain ‘world stuff’, came and went.
Much later, Boyle, an experimenter like Galileo and Bacon, and who was influenced much by
Descartes, lent important weight to the atomic theory of matter in the 1600s.
It was Lavoisier who wrote the first extensive list of elements - containing 33 elements. He distinguished between metals and non-metals, dividing the few elements known in the 1700's into four classes. Then John Dalton made atoms even more convincing, suggesting that the mass of an atom was it's most important property.
"The chemical elements are composed of... indivisible particles of matter, called atoms... atoms of the same element are identical in all respects, particularly weight." - Dalton
In the 1820's Jöns Jakob Berzelius developed a table of atomic weights, and introduced letters to symbolize elements, rather than the symbols originated by the early Greeks and following alchemists. Dobereiner noted that similar elements often had relative atomic masses, grouping elements in ‘triads’.
De Chancourtois made the first true periodic table, a spiral on a cylinder, to display the periodic reoccurrence of properties with an unbroken sequence of elements.
De Chancourtois’ telluric screw
Cannizaro determined atomic weights for the elements known in the 1860s, then a table was arranged by Newlands, with the elements given a numbers in series in order of their atomic weights, beginning with Hydrogen. This made evident that "The eighth element, starting from a given one, is a kind of repetition of the first", which Newlands called the Law of Octaves.
In 1869, Lothar Meyer compiled a Periodic Table of 56 elements based on the periodicity of properties such as molar volume when arranged in order of atomic weight. Both Meyer and Mendeleev constructed periodic tables independently that are credited as being the basis of the modern table. Meyer was more impressed by the periodicity of physical properties, while Mendeleev was more interested in the chemical properties.
The periodic law appears to have been independently formulated by at least six people within one decade - De Chancourtois, Newlands, Lothar Meyer, Mendeleev, Hinrichs, and Odling.
"...if all the elements be arranged in order of their atomic weights a periodic repetition of properties is obtained."
Mendeleev published his periodic table & law in 1869 and forecast the properties of missing elements, and chemists began to appreciate it when the discovery of elements predicted by gaps in his table took place. Periodic tables have always been related to the way scientists thought about the shape and structure of the atom, and has changed accordingly.
1894 Ramsay isolated Argon, and in the next year discovered helium. He went on to discover neon, krypton and xenon, and added a group to be called the Noble Gases.
Later, the table was reordered by Mosely according to atomic numbers (nuclear charge) rather than by weight, thereby modifying the Periodic Law.
The Periodic Law revealed important analogies among the 94 naturally occurring elements, and stimulated renewed interest in Inorganic Chemistry in the nineteenth century which has carried into the present with the creation of artificially produced, short lived elements of `atom smashers' and supercolliders of high energy physics.
Harry D. Hubbard, of the United States National Bureau of Standards, modernized Mendeleev's periodic table, and his first work was published in 1924. This was known as the "Periodic Chart of the Atoms".
Dr.Glenn T.Seaborg in 1968
Into the 1930s the heaviest elements were being put up in the body of the periodic table, and Glenn Seaborg "plucked those out" while working with Fermi in Chicago, naming them the Actinide series, which later permitted proper placement of subsequently 'created' elements - the Transactinides, changing the periodic table yet again. These elements were shown separate from the main body of the table.
When he examined the Alexander Arrangement, he said that it was correct, and later told a photographer (see photo) that it was his favorite periodic table.
The Alexander Arrangement of Elements, a three-dimensional periodic chart designed and patented (helical spiral segment basis of the patent shown at right) by Roy Alexander, retains the separate Lanthanide and Actinide series, but integrates them at the same time, made possible by using all three dimensions.
The periodic table has been improved continuously over the last century and a half, and the latest versions are built on the shoulders of many creative scientists.
An educational device designer, Roy Alexander, had in 1965, without knowledge of de Chancourtois’ Telluric Screw, returned dimension to the arrangement of the elements, again making possible element number continuity, easing both use & understanding of the immense correlative power of the periodic chart in teaching, learning, and working with chemistry.