Final answer:
John Dalton is recognized for the first atomic theory because he supported it with experimental evidence, unlike Democritus, who only had a philosophical standpoint. Thus, the correct answer is option d.
Step-by-step explanation:
John Dalton, a pioneering figure in the history of chemistry, is widely acknowledged for introducing the first atomic theory. In contrast to Democritus, who approached atoms from a philosophical standpoint, Dalton distinguished himself by grounding his ideas in empirical evidence. His revolutionary atomic theory was underpinned by meticulous experiments and chemical analyses, marking a departure from the theoretical nature of Democritus' atomistic concepts.
Dalton's approach adhered closely to the scientific method, contributing to the development of a more precise and systematic atomic framework. Notably, his theory emerged from a rigorous examination of experimental results, with a particular emphasis on the weights of diverse elements and compounds. This empirical foundation represented a significant leap forward compared to the speculative nature of Democritus' earlier atomic hypothesis. Dalton's commitment to empirical observation and scientific rigor laid the groundwork for the modern understanding of atoms, cementing his legacy as a key figure in the advancement of atomic theory.