Identify whether the following nuclide is stable or radioactive: Platinum-196, Francium-224, ⁶⁴₂₉Cu, ⁶⁰₂₈Ni, ⁹⁸₄₃Tc. Explain.

• A. Francium-224, ⁶⁴₂₉Cu and ⁹⁸₄₃Tc are stable because they have a stable neutron/proton ratio.
  ⁶⁰₂₈Ni and Platinum-196 are radioactive because they have an odd number of protons and neutrons.
• B. ⁶⁴₂₉Cu and ⁹⁸₄₃Tc are radioactive because they have an odd number of protons and neutrons.
  ⁶⁰ Francium-224, ₂₈Ni and Platinum-196 are stable because they have a stable neutron/proton ratio.
• C. Francium-224 is radioactive because it has a high atomic number.
  ⁶⁴₂₉Cu and ⁹⁸₄₃Tc are stable because they have a stable neutron/proton ratio.
  ⁶⁰₂₈Ni and Platinum-196 are radioactive because they have an odd number of protons and neutrons.
• D. Francium-224 is radioactive because it has a high atomic number.
  ⁶⁴₂₉Cu and ⁹⁸₄₃Tc are radioactive because they have an odd number of protons and neutrons.
  ⁶⁰₂₈Ni and Platinum-196 are stable because they have a stable neutron/proton ratio.

Answer: (D)