Mendeleev left some blank spaces in the periodic table for those elements, which were not known at that time. He had predicted that these elements would be discovered later on. He even had predicted the properties of these elements in the light of other elements present in the same group. Mendeleev named these elements by prefixing the Sanskrit word ‘Eka’ to the name of preceding element in the same group, i.e. Eka–boron for scandium, Eka–aluminium for gallium and Eka–silicon for germanium.