Question

______ are atoms with the same number of protons, but differing numbers of neutrons. a atoms b ions c isotopes d molecules

Explanation:

To solve this, we analyze each option:

• Option A: "Atoms" is a general term for the basic unit of matter, not specific to the given definition.
• Option B: "Ions" are atoms or molecules with a net electric charge (due to loss or gain of electrons), not related to neutron number differences.
• Option C: "Isotopes" are defined as atoms of the same element (same number of protons) with different numbers of neutrons, matching the description.
• Option D: "Molecules" are groups of atoms bonded together, not related to the proton - neutron relationship of single atoms.

Answer:

C. Isotopes