Answer:
D.) This atom has an atomic number of 50
Explanation:
A is wrong because we determine the type of atom by their number of protons, not the number of neutrons. This makes the atom Tin (Sn).
B is wrong because both protons and neutrons contribute to the weight of an atom, not just neutrons
C is wrong because the correct name for this isotope would be tin-119, which is calculated by adding the protons and neutrons
D is correct because isotopes of the same element always share the same atomic number
