Thermal neutrons are those which.

Options

A. Move with very high velocities
B. Have approximately the same kinetic energies as those of the surrounding molecules
C. Are at rest
D. Are at very high temperature

Answer

B

Explanation

Fast moving neutrons are allowed to pass through a moderator fike heavy water. When they collide with the molecules of the moderator, their speeds (kinetic energies) are considerably decreased (about 0.5 eV). Such neutrons are known as thermal neutrons.