G8 – A Method to the Madness: The Periodic Table 800-900L -03

Mendeleev wanted to construct a new model of the periodic table. He hoped he could create one that would make more sense than previous versions. At the time (circa (1868-1870), there were 60 elements that had been discovered. Mendeleev placed the names of these 60 elements onto cards. He placed the elements in rows and columns. He was in search of a noticeable pattern. He tried many variations. Finally, he decided to arrange them by weight. As he arranged the elements by weight, he realized something interesting. If arranged in this manner, the columns did represent elements with similar traits, but there was one problem. This method only worked if he skipped certain spots. This was a Eureka moment for Mendeleev. These missing spots, he surmised, must be elements not yet discovered.

In coming years, these spots were indeed filled in as scientists discovered new elements. Today, about 110 elements make up the modern periodic table. By looking for patterns, Mendeleev provided a new and unique way to organize the elements. By using his method, meaningful information about each element was predictable. It was simply a matter of its position on the table.

It was later found that Mendeleev’s method of arranging by weight had a great impact. His redesign of the periodic table led to many discoveries about the internal structure of the atom, for example, the number of protons in each atom. As you move across the rows, each element has one more proton than its neighbor to the left. This structure helped to explain the traits of atoms that made up the elements.