Which pair of atoms constitutes a pair of isotopes of the same element?

• A. 6 protons, 6 neutrons and 7 protons, 6 neutrons
• B. 7 protons, 7 neutrons and 8 protons, 8 neutrons
• C. 6 protons, 6 neutrons and 6 protons, 6 neutrons
• D. 6 protons, 6 neutrons and 6 protons, 7 neutrons

Answer: (D)

Verified step by step guidance

1. Recall that isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.
2. Identify the number of protons in each pair of atoms, since the number of protons defines the element.
3. Compare the pairs given: for example, the pair with 6 protons and 6 neutrons and the pair with 6 protons and 7 neutrons have the same number of protons but different neutrons, which fits the definition of isotopes.
4. Check the other pairs to confirm if they have the same number of protons; if not, they are not isotopes but different elements.
5. Conclude that the pair with 6 protons, 6 neutrons and 6 protons, 7 neutrons constitutes a pair of isotopes of the same element.