Questions: Select the correct answer. Which option describes a similarity and a difference between isotopes of an element? A. same atomic number; different number of protons B. same number of protons; different atomic number C. same atomic number; different mass number D. same mass number; different atomic number E. same number of neutrons; same number of protons

Solution Steps

Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons. This means that isotopes of an element have the same atomic number (since the atomic number is defined by the number of protons) but different mass numbers (since the mass number is the sum of protons and neutrons).

• Option A: "same atomic number; different number of protons" - This is incorrect because isotopes have the same number of protons.
• Option B: "same number of protons; different atomic number" - This is incorrect because isotopes have the same atomic number.
• Option C: "same atomic number; different mass number" - This is correct because isotopes have the same atomic number and different mass numbers.
• Option D: "same mass number; different atomic number" - This is incorrect because isotopes have different mass numbers.
• Option E: "same number of neutrons; same number of protons" - This is incorrect because isotopes have different numbers of neutrons.

Final Answer