Who was the first scientist to systematically determine atomic weights for elements?

• A. John Dalton
• B. Dmitri Mendeleev
• C. Antoine Lavoisier
• D. Marie Curie

Answer: (A)

Verified step by step guidance

1. This question is about the history of chemistry, specifically the development of atomic theory and atomic weights.
2. Atomic weights are the relative masses of atoms of different elements compared to a standard, usually hydrogen or oxygen.
3. John Dalton was the first scientist to systematically determine atomic weights by proposing that each element is made of atoms with a characteristic mass, and he assigned relative weights to these atoms based on experimental data.
4. Dmitri Mendeleev is known for creating the periodic table, arranging elements by atomic weight and properties, but he did not systematically determine atomic weights first.
5. Antoine Lavoisier is famous for establishing the law of conservation of mass and identifying elements, but he did not assign atomic weights systematically; Marie Curie is known for her work on radioactivity, not atomic weights.