What later evidence proved that mendeleev was correct?

Later evidence that supported Mendeleev's Periodic Table included the discovery of new elements, such as gallium and germanium, which matched his predictions for their properties and placements. Additionally, the development of atomic theory and the understanding of atomic structure revealed that elements' chemical properties are related to their atomic number, aligning with Mendeleev's arrangement. The periodic law, which states that the properties of elements are periodic functions of their atomic numbers, further validated his work. These findings confirmed the periodic table's utility and accuracy in organizing elements.