Final answer:
The number of neutrons (N) in an isotope can be calculated using the a-z-x notation. To calculate the number of neutrons, subtract the atomic number (Z) from the number of nucleons (A) in the nucleus.
Step-by-step explanation:
The number of neutrons (N) in an isotope can be calculated using the a-z-x notation. In this notation, A represents the number of nucleons (protons + neutrons) in the nucleus, X is the element symbol, Z is the atomic number (number of protons), and N is the number of neutrons. The relationship between A, Z, and N is defined as A = N + Z. Therefore, to calculate the number of neutrons, subtract Z from A. For example, if A = 20 and Z = 6, then N = A - Z = 20 - 6 = 14.