Dmitri Mendeleev is the scientist known for developing the periodic table of elements. In 1869, he organized elements based on their atomic mass and chemical properties, which revealed periodic patterns. Mendeleev’s table not only classified known elements but also predicted the existence and properties of undiscovered ones, allowing scientists to understand their behavior and facilitates the study of chemistry. His periodic law asserted that the properties of elements are a periodic function of their atomic weights, which was a groundbreaking advancement in the field. Mendeleev's work remains fundamental to modern chemistry and science education worldwide.