How many neutrons does the isotope nitrogen-15 have?

• A. 7
• B. 8
• C. 15
• D. 14

Answer: (A)

Verified step by step guidance

1. Identify the atomic number of nitrogen, which is 7. This number represents the number of protons in the nucleus of a nitrogen atom.
2. Understand that the mass number of an isotope is the sum of its protons and neutrons. For nitrogen-15, the mass number is 15.
3. Use the formula: \( \text{Number of neutrons} = \text{Mass number} - \text{Atomic number} \).
4. Substitute the known values into the formula: \( \text{Number of neutrons} = 15 - 7 \).
5. Calculate the result to find the number of neutrons in nitrogen-15.