Definition: Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.
Input: The point at which different radiometric isotopes begin diffusing into and out of the crystal lattice is called what no sorry I meant the point at which they stop diffusing into and out of crystal lattice?

The point at which different radiometric isotopes stop diffusing into and out of the crystal lattice is called what?