Final answer:
Curium-245 is an alpha emitter, and the nuclear reaction is 245Cm -> 4He + 241Pu, with plutonium-241 as the daughter isotope.
Step-by-step explanation:
Curium-245 (245Cm) is an alpha emitter. The emission of an alpha particle means that the nucleus of an atom loses two protons and two neutrons, which is the configuration of an alpha particle (4He2+). The nuclear reaction can be written as:
245Cm -> 4He + 241Pu
The atomic number of curium is 96, and when we subtract the two protons found in the alpha particle, the daughter isotope produced has an atomic number of 94, which identifies it as plutonium (Pu). The mass number also decreases by 4, from 245 to 241 for the plutonium isotope (hence 241Pu).