This is an approximation that is based on the fact that the electron is more than 1000 times lighter than the nucleus of the atom. It allows you to model the motion of electrons as being completely independent of the motion of nuclei because the motion of the nuclei is much much slower than that of electrons. For instance, when an molecule absorbs light such that its electronic configuration changes, that happens essentially immediately. Then the nuclei will move accordingly (either shortening or lengthening bond lengths for instance).
Hindu text
Parents of J. Robert Oppenheimer. Mother: Ella Friedman Father. Julius Oppenheimer
Just what it means in the Hindu Bagavad Gita.
June 7 1329 at the age of 54. his exact time was at 11:22 am..........okay fine I don't know the time.
Because he realized what a horrificly powerful weapon nuclear bombs actually are & he decided to compaign against the use of them after they were used in Japan.