Russian chemist and inventor, Dmitri Mendeleev, is said to be the creator of the modern periodic table. He knew of 63 elements and it’s said he wrote the names and properties of the elements on small cards which he then arranged in order of atomic weight. The cards then got rearranged, maintaining their order, into groups with similar properties. He then proposed the periodic law: ‘Elements have properties that recur or repeat according to their atomic weight.’
Previous scientists had attempted to logically organise the elements but Mendeleev was the first to leave ‘holes’ for elements not yet discovered, the properties of which could be predicted from the first periodic table. He also predicted the properties of six elements that could fill the ‘holes’. Three of those predictions he called ‘eka-silicon’, ‘eka-boron’ and ‘eka-aluminium’ (‘eka’ meaning ‘like’). Germanium, scandium and gallium were discovered with properties very similar to his predictions, respectively. This convinced many scientists of the accuracy, and value, of Mendeleev’s periodic table.