Question

Heavy water is a _____________, which slows down fast moving neutrons to thermal velocities

so that they can cause fission of uranium nuclei.​

Answer 1

Answer:

Heavy water (D2O), also called deuterium oxide

Explanation:

water composed of deuterium, the hydrogen isotope with a mass double that of ordinary hydrogen, and oxygen. (Ordinary water has a composition represented by H2O.)

Answer 2

Explanation:

Heavy water (D20) also called deuterium oxide.