Mendeleev went even further. He corrected the known atomic masses of some elements and he used the patterns in his table to predict the properties of the elements he thought must exist but had yet to be discovered. He left blank spaces in his chart as placeholders to represent those unknown elements.

Who made predictions about undiscovered elements?

Dmitri Mendeleev's detailed prediction in 1871 of the properties of three as yet unknown elements earned him enormous prestige.

Who discovered the pattern for the current periodic table?

Yet historians typically consider one event as marking the formal birth of the modern periodic table: on February 17, 1869, a Russian professor of chemistry, Dimitri Ivanovich Mendeleev, completed the first of his numerous periodic charts.