Question

which fact is true during a fission chain reaction? (1 point)
the total number of protons will increase 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.

Explanation:

• In a fission chain reaction, a heavy nucleus splits into smaller nuclei. During this process, neutrons are released. These neutrons can then cause further fission reactions.
• The number of protons is determined by the type of element (atomic number). In a fission reaction, the total number of protons (sum of protons in all resulting nuclei) remains the same as in the original nucleus (conservation of atomic number).
• However, the number of freely - moving neutrons increases. For example, when \(U - 235\) undergoes fission, one neutron causes the fission and more than one neutron is released. These released neutrons can go on to cause more fission reactions, leading to an increase in the number of freely - moving neutrons over time.

Answer:

The number of freely - moving neutrons increases over time.