Final answer:
Both isotopes 99Tc and 96Tc have an atomic number of 43, which means they contain 43 protons each. The atomic mass number of 99Tc is 99 with 56 neutrons, while 96Tc has an atomic mass number of 96 with 53 neutrons.
Step-by-step explanation:
To compare the atomic number, atomic mass number, and number of neutrons of 9943Tc and 9643Tc, we need to acknowledge that the atomic number (Z) represents the number of protons in the nucleus of an atom, which is consistent across all isotopes of an element. As such, both isotopes of technetium (Tc) have an atomic number of 43, indicating that they have 43 protons each.
The atomic mass number (A), which is the sum of protons and neutrons, is different for the two isotopes: 9943Tc has a mass number of 99, while 9643Tc has a mass number of 96.
The number of neutrons (N) can be found by subtracting the atomic number from the mass number. For 9943Tc, N = 99 - 43 = 56 neutrons, and for 9643Tc, N = 96 - 43 = 53 neutrons. Thus, the isotope 9943Tc has 3 more neutrons than the isotope 9643Tc.