Final answer:
Dmitri Mendeleev is renowned for creating the first periodic table of the elements in 1869, which organized elements by atomic mass and accurately predicted undiscovered elements. His contributions were acknowledged when element 101 was named mendelevium in his honor.
Step-by-step explanation:
Dmitri Mendeleev is best known for publishing the first periodic table of the elements in 1869. His work highlighted the periodic nature of the properties of elements, arranging them by atomic mass and revealing a pattern that showed similarities among elements. Mendeleev's contributions were recognized when element number 101, synthesized in 1955, was named mendelevium in his honor.
Mendeleev not only arranged the known elements in a systematic way but also predicted the existence and properties of elements that had not been discovered, such as gallium and germanium. These predictions, once confirmed with the discovery of these elements, solidified the credibility of Mendeleev's periodic table. Although contemporaneously, Lothar Meyer in Germany recognized a similar periodicity, Mendeleev is given more credit due to his accurate predictions and the earlier publication of his table.