The study of the dynamics of molecular valence electrons and their coupling with nucleus motion is a frontier in ultrafast physics and ultrafast chemistry. Here, we investigate the behavior of valence electrons and nucleus wavepackets on a femtosecond time scale by the time-resolved strong-field ion momentum spectroscopy. Two orientation-dependent bond-breakages of N2O molecules from the same electronic state are studied, and the evolution of dipole moment during molecular breaking on the asymmetric Pzsum distribution is analyzed, and thus the electron localization during the molecules dissociating into ions and atoms is captured. The overall agreement between experimental and theoretical results for the orientation-dependent dissociation dynamics promotes the understanding of the evolution of nucleus wavepackets and provides a basis for the control of molecular ultrafast chemical reactions.