Mendeleev's Predicted Elements Discovered in Sequence

Between 1875 and 1886, three elements predicted by Dmitri Mendeleev in his 1871 periodic table article were discovered in sequence. Paul Emile Lecoq de Boisbaudran identified gallium in 1875, matching Mendeleev's eka-aluminium predictions for atomic weight and density. Lars Fredrik Nilson discovered scandium in 1879, confirming eka-boron. Clemens Winkler isolated germanium in 1886, fulfilling eka-silicon. Each discovery closely matched Mendeleev's predicted properties, converting skeptics and establishing the periodic table as chemistry's organizing framework.