Which property distinguishes isotopes of the same element from each other?

• A. They have different numbers of electrons in their outer shell.
• B. They have different numbers of neutrons.
• C. They have different chemical symbols.
• D. They have different numbers of protons.

Answer: (B)

Verified step by step guidance

1. Recall that isotopes are atoms of the same element, meaning they have the same number of protons (which defines the element).
2. Understand that the chemical symbol of an element is determined by its number of protons, so isotopes share the same chemical symbol.
3. Recognize that electrons can vary in ions or charged species, but isotopes specifically differ in their nuclear composition, not electron count.
4. Identify that the key difference between isotopes lies in the number of neutrons in the nucleus, which affects the atomic mass but not the chemical properties significantly.
5. Therefore, the distinguishing property of isotopes is that they have different numbers of neutrons while having the same number of protons.