Which of the following is NOT one of Dalton's original hypotheses of atomic theory?

• A. Atoms of the same element are identical in mass and properties.
• B. Atoms cannot be created, divided, or destroyed in chemical reactions.
• C. Atoms combine in simple whole-number ratios to form compounds.
• D. Atoms contain protons, neutrons, and electrons.

Answer: (D)

Verified step by step guidance

1. Recall Dalton's original atomic theory, which was proposed in the early 19th century and laid the foundation for modern chemistry.
2. List Dalton's key hypotheses: (1) All matter is made of indivisible atoms, (2) Atoms of the same element are identical in mass and properties, (3) Atoms cannot be created, divided, or destroyed in chemical reactions, and (4) Atoms combine in simple whole-number ratios to form compounds.
3. Understand that Dalton's theory did not include the internal structure of atoms, such as protons, neutrons, and electrons, because these subatomic particles were discovered later.
4. Compare each given statement to Dalton's original hypotheses to identify which one does not belong to his theory.
5. Conclude that the statement 'Atoms contain protons, neutrons, and electrons' is NOT part of Dalton's original atomic theory because it reflects knowledge gained after Dalton's time.