Why did Dmitri Mendeleev make the periodic table?
Answers
Answer:
Mendeleev realized that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.
Explanation:
On 17 February 1869, Russian chemist Dmitri Mendeleev jotted down the symbols for the chemical elements, putting them in order according to their atomic weights and inventing the periodic table. He wrote down the sequence in such a way that they ended up grouped on the page according to known regularities or ‘periodicities’ of behaviour. It was perhaps the greatest breakthrough in the history of chemistry.
Mendeleev’s ideas, which built on the earlier work of French chemist Antoine Lavoisier in the previous century, totally changed the way chemists viewed their discipline. Now each chemical element had its number and fixed position in the table, and from this it became possible to predict its behaviour: how it would react with other elements, what kind of compounds it would form, and what sort of physical properties it would have.
Soon, Mendeleev was predicting the properties of three elements – gallium, scandium and germanium – that had not then been discovered. So convinced was he of the soundness of his periodic law that he left gaps for these elements in his table. Within twenty years, all three had been found, and their properties confirmed his predictions almost exactly.