Importance And Significance Of The Periodic Table
Scientists who have contributed to the development of the Periodic Table
The search for elements dates back to antiquity when metals like gold (Au), silver (Ag), tin (Sn), copper (Cu), lead (Pb) and mercury (Hg) were essential in the daily lives of the people that lived through the copper, bronze, middle and stone ages. …show more content…
Dalton born on the 6th of September, 1766 in England, had previously investigated gas laws, colour blindness and meteorology, however, none of those investigations are as well remembered as Dalton’s atomic theory. His atomic theory published in 1805 became the foundation in chemistry. His theory states that all matter is made of indivisible and indestructible atoms. Moreover, all atoms of a given element are identical in mass and properties. Compounds are formed by two or more kinds of atoms and chemical reactions are a rearrangement of atoms, (Leon, …show more content…
This is where he was able to discover isotopes of elements. According to kiwi web - the published results of Henry’s wavelength measurements of X-ray spectral lines of a number of elements showed that the ordering of the wavelengths f X-ray emissions of elements coincided with the ordering of elements by their number of protons. The faults in Dmitri Mendeleev’s periodic table such as ordering the table by atomic mass had disappeared by the 20th century with Mosely’s findings.
Left: American Chemist Henry Moseley. (Source: Mc Millan, 2015) Glenn Seaborg, an American born chemist made the last and most recent changes to the periodic table in 1940. Seaborg discovered plutonium and the transuranic elements from atomic number 94 to 102.
Left: An image of Glenn Seaborg (Source: atomicarchive.com, 2015)
The Evolution of Periodic Tables
Above: An image of John Newland’s table of elements 1864. (Source: Wikipedia, undated)
Above: An image of Dmitri Mendeleev’s periodic table of elements 1869. (Source: Neville,