The answer to this question wasn't simply academic and inherently interesting: it also held the promise that if such a system could be found, the existence and nature of hitherto unknown elements could be understood even before they were discovered. It would also help determine what chemists should look for when searching for new elements.
The problem, of course, was solving that intellectual puzzle. Different men of science adopted different criteria to solve this question. Some focused on atomic weight, others on the inherent properties of individual elements, and yet others focused on the periodicity with which certain similar properties were repeated. Unfortunately, because no single system could account for all known chemical properties, no consensus could be made.
That is, however, until Russian scientist Dmitri Mendeleev cracked nature's code and revealed one of science's most famous taxonomic charts: the periodic table of elements. This is the set of a priori principles that governs, explains and predicts the properties of all elements, sorts them according to a system of increasing weight, and categorizes them according to families of property similarity.
Once this system was in place, it wouldn't take too long for geniuses such as Ernest Rutherford to start understanding the basic structure of atoms. Here is that fascinating story:
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