History of the Periodic Table - Chemistry LibreTexts.pdf -...

11/11/21, 2:06 PM History of the Periodic Table - Chemistry LibreTexts
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History of the Periodic Table
The Periodic Table is for many the symbol of Chemistry. It is a single image that contains all of the known elements in the
universe combined into an easily readable table. There are many patterns present in the table as well. All of the elements
seem to fit together and connect to form a readable table and in turn the image of chemistry. The idea of elements first came
about in 300 B.C. The great Greek philosopher Aristotle conceived an idea that everything on earth was made up of these
elements. In ancient times, elements like gold and silver were readily accessible, however, the elements that Aristotle chose
were Earth, Water, Fire, and Air.
Figure : Dimitri Mendeleev
In 1649 the idea of elements took a huge step when Hennig Brand was the first to discover a new element: Phosphorous.
Brand was an alchemist in search of the Philosopher's Stone, or an object that would turn any ordinary metal into gold. In
his search he tried everything, including distilling human urine. When that experiment was carried out Brand found a
glowing white rock. This was the new element he would call Phosphorous. The alchemists and scientists of the
enlightenment period added incredible amounts of knowledge to the ideas about elements. In 1869 there were already 63
elements that had been discovered. With each new element that was found, scientists began to realize that there were
patterns developing and some started to put the elements into a table.
Scientists like John Newlands and Alexandre-Emile Béguyer de Chancourtois formed their own versions of periodic tables.
These versions were relatively simple though and were also somewhat obscure and hard to read. The scientist who brought
it all together was Dmitri Mendeleev (1834 to 1907). Mendeleev was a Russian born chemist and the first to publish a
modern version of the periodic table. His table ordered the elements by atomic weights (molar masses). When the elements
were ordered by their atomic weights, they exhibited similar chemical properties. The table that Mendeleev compiled was so
good that he was able to predict elements that were not even known to him at the time. These elements included
germanium, gallium, and scandium. There were some pitfalls to the table though. Since not all of the elements had been
discovered at the time of Mendeleev's publishing, he left out important elements like the noble gases. After Mendeleev's