How many protons does the isotope nitrogen-15 have?

• A. 8
• B. 6
• C. 7
• D. 15

Answer: (C)

Verified step by step guidance

1. Identify the element in question, which is nitrogen. The atomic number of nitrogen determines the number of protons it has.
2. Recall that the atomic number (Z) of an element is equal to the number of protons in its nucleus. For nitrogen, the atomic number is 7.
3. Understand that the isotope notation nitrogen-15 means the isotope has a mass number (A) of 15, which is the sum of protons and neutrons.
4. Since the number of protons is fixed for an element, nitrogen-15 has the same number of protons as any nitrogen atom, which is 7.
5. Therefore, the number of protons in nitrogen-15 is 7, regardless of the isotope's mass number.