Which fact is true about a fission chain reaction?
The total number of protons will increase over time
The number of freely-moving neutrons increases over time
The total number of protons will decrease over time
The number of freely-moving neutrons decreases over time
The number of freely-moving neutrons increases over time.
The correct fact about a fission chain reaction is: The number of freely-moving neutrons increases over time.
The correct answer is: The number of freely-moving neutrons increases over time.
Explanation:
A fission chain reaction refers to the process of splitting an atomic nucleus into two smaller nuclei, which releases a large amount of energy in the form of heat and radiation. During this process, a neutron is usually absorbed by a heavy nucleus, causing it to become unstable and split into two smaller nuclei, as well as releasing two or three additional neutrons. These released neutrons can then go on to initiate the fission of other nuclei, thus creating a chain reaction.
As each nucleus undergoes fission, it releases additional neutrons, which then go on to collide with other nuclei and cause them to split. Thus, the number of freely-moving neutrons in the system increases over time as the chain reaction progresses.
On the other hand, the total number of protons remains constant throughout the process, as the total number of protons in the system is conserved during fission reactions.
Therefore, the correct answer is that the number of freely-moving neutrons increases over time in a fission chain reaction.