A. Silicon
B. Beryllium
C. Lead
D. Zirconium
By Team Aakash Byju's | 29th October 2022
A chain reaction takes place in nuclear fission. It is a process of the release of neutrons that leads to additional fission to at least one further nucleus.
Each newly produced nucleus produces neutrons again and continues the process of nuclear fission.
To stop this chain reaction, the control rods made up of materials with high neutron absorption cross-sections are used.
Basically, the material should reflect the neutrons to reduce their speed hence slowing down the chain reaction.
Compared to all materials provided as options, Beryllium is the best material for moderators.
Beryllium has a stable electron configuration thus the released neutrons in nuclear fission fail to find target nuclei to proceed with the chain reaction.