historical development of the periodic table

The periodic table evolved through centuries of scientific discovery. In the early 19th century, scientists like John Dalton began classifying elements based on atomic weights. Dmitri Mendeleev, in 1869, created a table that arranged elements by increasing atomic weight, revealing patterns in their properties and predicting undiscovered elements. Later, Henry Moseley redefined the organization by atomic number rather than weight. The modern periodic table includes over 100 elements, organized into groups and periods, highlighting relationships and trends in chemical behavior, reflecting our deepening understanding of atomic structure and the nature of matter.