Final answer:
D) John Dalton discovered a number of atomic weights of elements in the early 1800s based on a comparison to hydrogen. His research was the foundation for the development of the periodic table by Dmitri Mendeleev.
Step-by-step explanation:
In the early 1800s, John Dalton discovered a number of atomic weights of elements based on a comparison to hydrogen. Dalton determined the atomic weights of various elements and compounds by studying their weights and observing that matter combined in fixed ratios based on weight.
His research on atomic weights was the foundation for the development of the periodic table by Dmitri Mendeleev.