The Russian scientist who related chemical properties and atomic masses was Dmitri Mendeleev. He is famous for creating the periodic table of elements, which organizes elements by their atomic number and recurring chemical properties.

Mendeleev's work was groundbreaking because it:

* Predicted the existence of undiscovered elements: He left gaps in his table for elements that hadn't been discovered yet, and his predictions about their properties turned out to be remarkably accurate.

* Showed the periodic nature of chemical properties: He noticed that elements with similar chemical properties appeared at regular intervals in his table, leading to the concept of periodicity.

While other scientists, like Lothar Meyer, were working on similar ideas, Mendeleev's contributions are widely considered more significant due to the predictive power of his table and his bold use of it to revise the atomic weights of some elements.