In 1869 the Russian chemist Dmitri Mendeleev came up with organizing the elements according to their atomic weight in the form of rows and columns that had been known at that time.
He had a very genius mind,because he had left gaps in his periodic table which had not been discovered during his time.
But,he was able to predict the existence and also the properties of these elements
Sorry,the image is not clear,See clear images in Google images
As a honor of him the element "Mendelevium" with atomic number 101 was named after him
Watch a clear video about him