How did John Dalton use chemical evidence to support the existence of atoms?

John Dalton supported the existence of atoms by using experimental chemical evidence to demonstrate that elements combine in fixed, predictable ratios. By analyzing the weights of elements in various compounds, he formulated the law of multiple proportions, which states that when two elements form more than one compound, the masses of one element that combine with a fixed mass of the other exist in a ratio of small whole numbers.1234

Dalton reasoned that these regularities in stoichiometry could only be explained if matter consisted of discrete, indivisible particles—atoms—that possessed distinct, characteristic masses. He proposed that different compounds were formed by combining these atomic building blocks in different whole-number ratios. Although his specific formulas for compounds were sometimes incorrect due to the limitations of 19th-century analytical data, his foundational argument that each element is characterized by its own unique type of atom provided a powerful, logical framework that transformed atomic philosophy into a rigorous scientific theory.324