oct 5, 1803 - John Dalton
Description:
Date: 1803-1808Country: Britain
Observations/Experiments/Evidence: Used the Law of Conservation of Mass (Lavoisier, 1789), Law of Constant Composition (Proust, 1799), and Law of Multiple Proportions (Dalton) as evidence for his discoveries.
Discoveries/Conclusions: John Dalton said that matter is composed of atoms, all atoms of one element are the same as each other, and that when a chemical reaction occurs the rearrangement of atoms are in simple whole number ratios.
Contribution: John Dalton’s law of multiple proportions and his observations lead to a much greater understanding of what atoms are.
Added to timeline:
Date:
oct 5, 1803
Now
~ 221 years ago