Final answer:
When curium-242 undergoes alpha decay, it emits an alpha particle and produces the isotope plutonium-238. Alpha decay decreases the atomic number by 2 and the mass number by 4, leading to the production of plutonium-238. Therefore, the correct answer to the question is B. 238 Pu.
Step-by-step explanation:
The question is about what isotope is produced when curium-242 undergoes alpha decay. In an alpha decay process, an alpha particle, which consists of two protons and two neutrons, is emitted from the nucleus of an atom. This results in the formation of a new atom with an atomic number that is two less than the original atom and a mass number that is four less. For curium-242 (242Cm), the alpha decay equation would be written as: 242Cm → 4He + Daughter Isotope
To find the daughter isotope, we start with the original atomic number of curium, which is 96, and subtract the atomic number of the alpha particle, which is 2 (from the 2 protons). This leaves us with 94, which corresponds to plutonium (Pu). The mass number follows the same process: starting with 242 and subtracting 4 (from the 2 protons and 2 neutrons in an alpha particle), we end up with 238. Thus, curium-242 decays to produce plutonium-238 (238Pu). Therefore, the correct answer to the question is B. 238 Pu.