In 1869, when Mendeleev proposed his periodic table, he noted gaps in the table and concluded that in these gaps belonged elements yet to be discovered. Based on other elements in the same group he predicted the existence of eka-aluminum, eka-boron and eka-silicon with respective atomic masses of 44,68, and72. These elements were later named as gallium (Ga), scandium (Sc) and germanium (Ge).