The study of molecular valence electron dynamics and their coupling with nuclear motion is one of the frontiers of ultrafast physics and ultrafast chemistry. With time-resolved strong-field ion momentum spectroscopy, we study electron valence and nucleus wavepacket evolution on a femtosecond timescale. Two orientation-dependent bond-breaks of N2O molecules from the same electronic state are studied, and the influence of orbital hybridization and polarization effect during molecular breaking is analyzed based on the measured time-resolved asymmetric Pzsum distributions, allowing a visual representation of electron localization during the dissociation of molecules into ions and atoms. Comparison of experimental and theoretical results on orientation-dependent dissociation dynamics allows us to understand how nuclear motions evolve during fragmentation and to control ultrafast molecular reactions. Ultrafast spectroscopy allows for the real-time observation of molecular processes and enables a better understanding of the electron dynamics and nuclear evolution that occur during a chemical reaction. Here, the authors study, experimentally and theoretically, the electron localization that occurs on a femtosecond timescale during the dissociation of N2O. [ABSTRACT FROM AUTHOR]