According to Dalton's atomic theory, compounds are made up of which of the following?

• A. Molecules of the same element
• B. Atoms of different elements combined in fixed ratios
• C. Electrons and protons
• D. Isotopes of a single element

Answer: (B)

Verified step by step guidance

1. Recall Dalton's atomic theory, which states that compounds are formed when atoms of different elements combine in specific, fixed ratios.
2. Understand that molecules of the same element do not form compounds; they form elemental molecules, not compounds.
3. Recognize that electrons and protons are subatomic particles, not the fundamental units that combine to form compounds according to Dalton's theory.
4. Note that isotopes are variants of the same element with different numbers of neutrons, so they do not combine to form compounds.
5. Conclude that the correct description of compounds according to Dalton's atomic theory is that they are made up of atoms of different elements combined in fixed ratios.