( array |c|l|c|l| & Column 1 & & Column 2 (A) & Nuclear reactor & (P) & Device used to detect & & & ionizing radiation (B) & Geiger-Muller counter & (Q) & Converts nuclear energy into & & & electrical energy (C) & Controlled chain reaction & (R) & Maintained in a nuclear reactor to & & & produce energy at a steady rate (D) & Critical mass & (S) & Minimum amount of fissile material & & & needed to sustain a chain reac

Step-by-step solution

- (A) Nuclear reactor: A nuclear reactor ((Q) ) is a device used to initiate and control a sustained nuclear chain reaction to produce energy, primarily electrical energy. - (B) Geiger-Muller counter: A Geiger-Muller counter (P) is a common instrument used for detecting and measuring ionizing radiation. - (C) Controlled chain reaction: A controlled chain reaction ((R) ) is the process maintained in a nuclear reactor where neutrons released from fission cause further fission reactions, but at a controlled rate to pr