On the periodic table, germanium was predicted as “eka-silicon” by Dmitri Mendeleev.
In 1871, Mendeleev used gaps in his periodic arrangement to predict an undiscovered element below silicon. He called it eka-silicon, using “eka,” meaning “one” in Sanskrit, to indicate that it was one position below silicon in the same group.
Germanium was discovered in 1886 by Clemens Winkler in the mineral argyrodite. Its measured properties closely matched Mendeleev’s predictions, providing powerful evidence that the periodic table reflected real chemical patterns rather than being merely a list arranged by atomic weight.
Germanium has atomic number 32 and symbol Ge. It is a metalloid used in fiber-optic systems, infrared optics, semiconductor technology, and some solar cells. Gallium was another successful Mendeleev prediction, but it was his “eka-aluminium,” not eka-silicon.