Answer:
Maybe try to memorize it by the valence electrons. You can do this!!
Answer : The main function of the control rods in a nuclear power plant is to absorb the unwanted extra neutrons emitted after the nuclear fission reaction, as to slow down or completely shut down the reaction in case of certain emergencies.
The main idea is to prevent uncontrolled chain reactions which occurs in nuclear fission reactors. The important characteristic of a control rod should be made of a material which does not undergoes fission.
Answer:
This process is known as doping. It can be done by adding either of two types of impurity to the crystal. (A) By adding electron rich impurities i.e., group 15 elements to the silicon and germanium of group 14 elements.
This is what I found. Hope this helps:)