How do the isotopes of a given element differ from one another?

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

Answer: (A)

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 another subatomic particle.
2. Understand that the number of protons defines the element and its chemical symbol, so isotopes cannot differ in protons or chemical symbols.
3. Recognize that isotopes differ in the number of neutrons, which affects the atomic mass but not the chemical properties significantly.
4. Note that because isotopes have the same number of protons, they belong to the same element, not different elements.
5. Conclude that the key difference between isotopes of a given element is the number of neutrons they contain.