Nitrogen (N2) is an abundant diatomic molecule that makes up 78% of the Earth's atmosphere. It is therefore highly desirable to include this typically inert molecule in the syntheses of valueadded products or to use it as reservoirs of chemical energy. Industrially, atmospheric nitrogen enters the synthetic cycle through the well-established Haber-Bosch process, in which N2 is hydrogenated to ammonia at high temperature (500°C) and pressure (200 atm). The extreme reaction conditions required for such an important economical process have significant energy consequences, consuming approximately 1 % of the worldʼs energy supply, mostly in the form of pollution-intensive coal. 2c Indeed, the thermodynamic stability of N2 molecule makes its use dependent on surmounting significant energy barriers and requires an activation step to cleave N≡N bond. Therefore, many works have been developed to increase the efficiency of the dissociation of N≡N bond, mostly by using heterogeneous catalysts, such as reactive metallic surfaces. Dissociation of N2 molecules is usually carried out at high temperature and high pressure because N2 molecules weakly interact with most surfaces below room temperature (RT), and remains physisorbed (i.e. non-dissociated). The development of new strategies to dissociate N2 molecule under mild conditions is of critical interest. Molecule-surface collisions represent an interesting alternative because these collisional processes induce mechano-chemical or electron-transfer reactions that promotes dissociation of reactants at low pressure and low temperature. The conversion of kinetic energy into vibrational excitation following the collision of molecules with a surface was mainly investigated for hydrocarbon-based species 5a-b , even if few examples of the dissociation of N2 using a supersonic molecular beam to overcome the dissociation barrier via an hyperthermal collision were also investigated on metal surfaces. 5e-f These vibrational excitations can lead to dissociative states of the incident molecules, and result into the adsorption of dissociated fragments. One of the main interests of this mechanochemical reactivity is to be carried out at low pressure, typically in ultra-high vacuum, which allows the use of scanning probe microscopies to identify the adsorbed products resulting from the collisions. In the case of electron-transfer induced by molecular collision, a recent study showed that C=O bond of CO2 molecules can be cleaved by a non-uniform charge transfer from the substrate to CO2 molecules due to the conversion of kinetic energy of incident CO2 molecules into molecular deformation. 5i However, no study has been reported for the dissociation of inert molecules like N2 using a similar activated electron-transfer mechanism on non-metallic surfaces. Here, we demonstrate that the collisional dissociation of N2 is successfully achieved at very low pressure and at room temperature on the Si(111)-7x7 surface. The dissociation of N2 was investigated by scanning tunnelling microscopy (STM), Xray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations. This is the first report demonstrating that the Si(111)-7x7 surface can be used for a facile dissociation of inert molecules, paving the way for the development of new surface chemistry.