How do isotopes of a given element differ from each other?

• A. They have different numbers of protons.
• B. They have different chemical symbols.
• C. They have different numbers of neutrons.
• D. They belong to different elements.

Answer: (C)

Verified step by step guidance

1. Recall that isotopes are variants of the same element, meaning they have the same number of protons but differ in the number of neutrons.
2. Understand that the number of protons defines the element's identity and its chemical symbol, so isotopes cannot differ in protons or chemical symbols.
3. Recognize that isotopes have the same atomic number (number of protons) but different mass numbers due to varying neutrons.
4. Note that different elements have different numbers of protons, so isotopes cannot belong to different elements.
5. Therefore, the key difference between isotopes of a given element is the number of neutrons they contain.