Which statement about isotopes is correct?

• A. Isotopes of an element have different chemical symbols.
• B. Isotopes of an element have different numbers of protons and the same number of neutrons.
• C. Isotopes of an element always have different atomic numbers.
• D. Isotopes of an element have the same number of protons but different numbers of neutrons.

Answer: (D)

Verified step by step guidance

1. Recall the definition of isotopes: isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.
2. Understand that the chemical symbol of an element is determined by its number of protons (atomic number), so isotopes share the same chemical symbol because they have the same number of protons.
3. Recognize that the atomic number (number of protons) remains constant for isotopes, so statements claiming different atomic numbers for isotopes are incorrect.
4. Note that isotopes differ in their mass number because the number of neutrons varies, which affects the atomic mass but not the chemical identity.
5. Conclude that the correct statement about isotopes is that they have the same number of protons but different numbers of neutrons.