question_answer

At what temperature does all molecular motion cease? Explain.      Or Molecular motion ceases at zero kelvin. Explain.                                              

Answer:

                All molecular motion ceases at absolute zero or at\[0K\]. According to the kinetic interpretation of temperature,                 \[\overline{E}=\frac{3}{2}{{k}_{B}}T\] or \[T=\frac{2}{3}\frac{{\bar{E}}}{{{k}_{B}}}\] or absolute temperature \[\propto \] average K.E. of molecules \[\therefore \] The temperature \[=\text{ }0\text{ K},\] average \[\text{K}.\text{E}.\text{ }=\text{ }0\]. Thus at \[0K\], the velocity of molecules becomes zero.