Which statement best describes the existence of nitrogen-14 and nitrogen-15 isotopes?

• A. Nitrogen-14 and nitrogen-15 have different numbers of protons and the same number of neutrons.
• B. Nitrogen-14 and nitrogen-15 have identical atomic masses.
• C. Nitrogen-14 and nitrogen-15 are different elements.
• D. Nitrogen-14 and nitrogen-15 have the same number of protons but different numbers of neutrons.

Answer: (D)

Verified step by step guidance

1. Recall that isotopes of an element have the same number of protons but differ in the number of neutrons.
2. Identify that nitrogen has an atomic number of 7, meaning every nitrogen atom has 7 protons regardless of the isotope.
3. Understand that nitrogen-14 and nitrogen-15 differ in their mass numbers, which represent the total number of protons and neutrons.
4. Calculate the number of neutrons in each isotope by subtracting the atomic number from the mass number: for nitrogen-14, neutrons = 14 - 7; for nitrogen-15, neutrons = 15 - 7.
5. Conclude that nitrogen-14 and nitrogen-15 have the same number of protons (7) but different numbers of neutrons (7 and 8 respectively), which defines them as isotopes of the same element.