Chemistry

Question Analysis
This question tests the student's understanding of the relationship between the number of protons, neutrons, and the mass number of an isotope.

Key Concept Explanation
The mass number (A) of an isotope is the sum of the number of protons and neutrons in the nucleus. The atomic number (Z) is the number of protons, which remains constant for a given element.

Step-by-step Solution
1. Identify the number of protons (Z) and neutrons (N).
2. Use the formula: Mass number (A) = Number of protons (Z) + Number of neutrons (N).
3. Sub...