Which isotope, when bombarded with nitrogen-15, yields the artificial isotope dubnium-260 plus 4 neutrons

Question

Quizplus · Accepted Answer

According to the given information, the isotope must yield dubnium-260 (element with atomic number 105) and 4 neutrons. This means that the sum of the atomic numbers of the reactant and the nitrogen-15 target nucleus must be equal to 105 (dubnium's atomic number) and the sum of the mass numbers of the reactant and the nitrogen-15 target nucleus must be equal to 260 + 4 = 264. Among the choices given, only californium-249 (choice D) satisfies these conditions:

249 (atomic number of Cf) + 15 (atomic number of N) = 264 and 
249 (mass number of Cf) + 15 (mass number of N) = 260 + 4 = 264.

Therefore, the best choice is D.

Which Isotope, When Bombarded with Nitrogen-15, Yields the Artificial Isotope