History of the Periodic Table

The video explores the evolution of the periodic table, starting with 19th-century chemists' attempts to order elements by atomic weights. It covers John Dalton's early table, the discovery of element triads, and John Newlands' law of octaves. Dmitri Mendeleev's significant contributions, including his predictions of undiscovered elements, are highlighted. The video concludes with Henry Moseley's work on atomic numbers, which validated Mendeleev's table and corrected element order based on X-ray emissions.

How did Mendeleev justify leaving gaps in his periodic table?

What was one of the major adjustments made to the periodic table in the early 20th century?

What role did Henry Moseley play in the development of the periodic table?