'Heavy water' is a term related to which of the following?

Correct option is B

The correct answer is option (b): Nuclear power generation plants
Explanation:

• Heavy water (D₂O) is water in which the hydrogen atoms are replaced with deuterium, a heavier isotope of hydrogen.
  
• It is primarily used as a moderator and coolant in nuclear reactors, especially in pressurized heavy water reactors (PHWRs).
• Heavy water slows down neutrons in the reactor, making them more effective at sustaining the nuclear fission chain reaction.
• It is crucial for reactors that use natural uranium as fuel, as it helps achieve efficient energy production without requiring enriched uranium.
  

Information Booster:

Hydrogen has three naturally occurring isotopes, which differ in the number of neutrons in their nuclei:

1. Protium: $${}^1H$$

• Composition: 1 proton, 0 neutrons.
• Abundance: Most common isotope (about 99.98% of hydrogen found in nature).
• Mass Number: 1.
• Symbol: $1H$ or simply HHH.
• Properties: Lightest and simplest isotope of hydrogen, commonly used in chemical reactions and everyday applications.

2. Deuterium: $${}^2H$$​

• Composition: 1 proton, 1 neutron.
• Abundance: Relatively rare (~0.02% of hydrogen in nature).
• Mass Number: 2.
• Symbol: $2H$ or DDD (commonly called "heavy hydrogen").
• Properties: Used in nuclear reactors (heavy water, $DO$) and research involving isotopic labeling.

3. Tritium: $${}^3H$$​

• Composition: 1 proton, 2 neutrons.
• Abundance: Extremely rare in nature; produced artificially in nuclear reactors.
• Mass Number: 3.
• Symbol: $3H$ or TTT.
• Properties: Radioactive with a half-life of about 12.3 years, used in nuclear fusion research, self-powered lighting, and as a tracer in biochemical studies.