Dimitri Mendeleev discovered the Periodic Table. Mardelev was born in Siberia near Russia and his mother moved all of his 14 siblings so that he could have an education. He was the only one to go to school let alone college! He sat up all night with flash cards with the known elements and atomic numbers on them and made a crucial discovery. He realised that people may not have found all the elements so he left gaps in his works. People thought he was crazy but when they discovered the remaining elements, the element fitted in!! He didn't actually invent the table. He created it.
a russian scientist called Dmitri Mendeleev in 1869.he arranged elements in order of increasing RAM.although his periodic table had many gaps,he predicted that there were elements that could fill the gaps and even predicted their properties.elements like scandium,gallium,germacium etc.