The History of the Periodic Table

We can say that the development of the Periodic Table started with German chemist Johann Wolfgang Döbereiner. In 1817, Döbereiner put forward his idea of Triads. He put elements with similar chemical properties and orderly physical properties into groups of three. This layout of the elements was rejected, as Döbereiner could only make five Triads out of the then known 42 elements.

Later, in 1864, John Newlands (an English chemist) proposed the Newlands Octaves. He ordered them by their atomic mass and realised that every eighth element had a similar property to the first element. However, this too was rejected, as, after the first 18 elements, it became strange. Iron, a metal, was in the same group as Oxygen and Sulphur, two non-metals. Newlands table did show promise of future improvement, as it introduced some sense of periodicity.

And so, in the 1860s, there were 60 known elements that were arranged in the table by their atomic masses.

In 1869, Dmitri Mendeleev published his Periodic Table. It ordered all of the elements by atomic mass, but also split them up into periods based upon similar physical and chemical properties, determined by experiments in the lab. Mendeleev…