A two-step nuclear scheme is proposed: Step I: Four nuclei fuse to form one nucleus
PHYSICS · Single correct · AP · Physics 2: Algebra-based · Modern Physics · Modern Physics
Problem
A two-step nuclear scheme is proposed:
Step I: Four 4He nuclei fuse to form one 16O nucleus.
Step II: The resulting 16O nucleus subsequently splits into two 8Be nuclei.
Based solely on typical trends of average binding energy per nucleon with mass number, which statement best describes the net energy change for the entire two-step sequence?
(a) Net release of energy, because fusion in Step I liberates energy and for nuclei lighter than iron the release always outweighs any subsequent processes.
(b) Net absorption of energy, because Step I releases energy but Step II absorbs a slightly larger amount.
(c) No significant energy change, because the energy released in Step I almost exactly cancels the energy absorbed in Step II.
(d) Net absorption of energy, because both steps move the system away from the region of maximum binding energy near iron, so each step must absorb energy.