The idea that everything is made up of a combination of basic units was first fronted in the early 4th Century BC by Empedocles, a renowned philosopher of the time. Empedocles had stated in 330 BC that everything is a result of mixing of roots, and the idea was later embraced by Plato who classified the roots into four elements; fire, water, earth, and air. Ancient India also had a similar view on the composition of matter. However, it was not until the 17th Century AD that the first true element was discovered when Henning Brand discovered phosphorus in an experiment he conducted in 1669. The German merchant named his discovered element “cold fire.” Robert Boyle would later rediscover the element in 1680, ushering science into the unknown world of the elements.
The first chemistry textbook was written in the late 18th Century by Antoine Laurent de Lavoisier entitled “Elementary Treatise of Chemistry.” The French scientist recognized the existence of elements in his book, defining them as the basic building blocks of a substance, and could not be further broken down chemically. The book outlined some of the elements and was a precursor of the periodic table. Some of the elements that appeared in the book include mercury, hydrogen, zinc, oxygen, and phosphorus among others. Nonetheless, the book was vague in its classification of the elements, as Antoine Laurent de Lavoisier only categorized them into metals and non-metals.
The 19th century saw the first attempt to classify elements based on their respective atomic weights. Johann Dobereiner was the first scientist to attempt and introduced the Triad Law in 1829, which he used to classify the elements into four groups and each comprised of three elements, and defined the groups as “triads.” Later in the century, in 1862, the first true periodic table was introduced by a French geologist, Alexandre-Emile Beguyer de Chancourtois. The geologist’s periodic table was based on the element tellurium, after which it was named the “telluric helix.” John Newlands, a chemist from England, came up with a version of the periodic table that he called the “law of Octaves.” The English scientist had grouped the elements into eight categories in 1864, but his work was met with criticism and even ridicule from his peers at the Chemistry Society.
The Mendeleev Periodic TableDmitri Mendeleev first created the earliest version of the modern periodic table. The Russian scientist made his periodic table in 1869 after classifying elements based on their respective atomic mass and made his table public in March 1869 in a presentation to the Chemistry Society of Russia. The periodic table was unlike any other made before and also portrayed an unprecedentedly high level of accuracy. The Russian chemist also left blank spaces on his periodic table as he foresaw the discovery of new elements. Surprisingly, many of the elements that were discovered after the creation of the Mendeleev periodic table fit perfectly in the blank spaces including all the elements known as “noble gases.” Only a few elements that were discovered later were problematic to fit into Mendeleev’s periodic table and it includes elements such as radium and polonium.