Which of the following statements is inconsistent with Dalton's atomic theory as it was originally stated?

• A. Atoms of different elements have different properties.
• B. Atoms cannot be created or destroyed in chemical reactions.
• C. Atoms of the same element can have different masses.
• D. All matter is composed of indivisible atoms.

Answer: (C)

Verified step by step guidance

1. Step 1: Recall the key postulates of Dalton's atomic theory as originally stated. These include: (a) All matter is composed of indivisible atoms, (b) Atoms of the same element are identical in mass and properties, (c) Atoms of different elements have different properties, and (d) Atoms cannot be created or destroyed in chemical reactions.
2. Step 2: Analyze each given statement in the problem and compare it to Dalton's original postulates. For example, 'Atoms of different elements have different properties' aligns with Dalton's theory.
3. Step 3: Identify the statement 'Atoms of the same element can have different masses.' This contradicts Dalton's postulate that atoms of the same element are identical in mass and properties.
4. Step 4: Understand that the concept of isotopes (atoms of the same element with different masses) was discovered after Dalton's time, so this statement is inconsistent with his original theory.
5. Step 5: Conclude that the inconsistent statement with Dalton's atomic theory is 'Atoms of the same element can have different masses,' while the other statements are consistent with his original ideas.