What fact is true during a fission chain reaction?
• The number of freely-moving neutrons decreases over time
• The number of freely-moving neutrons increases over time
• The total number of protons will increase over time
• The total number of protons will decrease over time
The number of freely-moving neutrons increases over time.
During a fission chain reaction, the number of freely-moving neutrons increases over time.
The correct answer is: "The number of freely-moving neutrons increases over time."
During a fission chain reaction, a neutron initiates the splitting (fission) of a nucleus, which releases energy and additional neutrons. These newly released neutrons can then collide with other nuclei, causing them to fission as well and release even more neutrons. This process creates a chain reaction, where the number of freely-moving neutrons in the system continually increases over time.
To determine the correct answer, you can think about the key characteristics of a chain reaction. In a fission chain reaction, the goal is to sustain a self-sustaining reaction by having each fission event produce more than one neutron to continue the chain. If the number of freely-moving neutrons were to decrease over time, the chain reaction would eventually stop. Therefore, it is logical to conclude that the number of freely-moving neutrons increases over time during a fission chain reaction.