Final answer:
Adding neutrons to the atomic number gives the mass number, which is essential for identifying isotopes and balancing nuclear equations.
Step-by-step explanation:
When you add the number of neutrons (neutron number, N) to the atomic number (number of protons, Z), you obtain the mass number (A) of an element's isotope. This relationship is crucial in understanding nuclear chemistry, especially when determining the different isotopes of an element, which have the same number of protons but vary in their number of neutrons.
For example, in the element nickel which has an atomic number of 28, if the atom of nickel contains 31 neutrons, its mass number would be 28 (atomic number) + 31 (neutrons) = 59 (mass number). This is essential for identifying or predicting the behavior of isotopes in nuclear reactions, where both protons and neutrons must be conserved. The mass number helps to identify the specific isotope of an element and serves as a basis for writing balanced nuclear equations, like Beta decay or nuclear fission and fusion processes.