The discussion revolves around the historical context of Dmitri Mendeleev's development of the Periodic Table and his predictions regarding missing elements. Participants explore how Mendeleev identified gaps in the table and the patterns he may have observed in elemental properties.
Participants express differing views on the nature of Mendeleev's predictions and the implications of periodicity. Some agree on the existence of patterns, while others question the ease of predicting undiscovered elements.
Participants reference specific historical anecdotes and examples, but there is a lack of consensus on the methods Mendeleev used to predict missing elements and the reliability of his assertions.
http://www.slate.com/id/2258112/entry/2257317/Mendeleev picked apart Lecoq de Boisbaudran's data on the new element (soon named gallium). Mendeleev claimed, largely without evidence, that the accomplished Lecoq de Boisbaudran must have made mistakes when measuring gallium's weight and density, since they differed from Mendeleev's predictions.
The chutzpah here is incredible, but Mendeleev tended to trust his own instincts and formulas over mere evidence. Crackpots often do. The difference between Mendeleev and most crackpots is that Mendeleev was right: Lecoq de Boisbaudran soon had to publish an embarrassing retraction about gallium's weight and density, changing them to values that vindicated Mendeleev. According to science philosopher and historian Eric Scerri, "The scientific world was astounded to note that Mendeleev, the theorist, had seen the properties of a new element more clearly than the chemist who had discovered it."
FantasyQueen said:How did Dimitri Mendeleev know that some of the elements were missing/not discovered? How did he know that the missing elements existed? Did he find some sort of pattern when he created the Periodic Table?