To sum up, we have successfully demonstrated that N2 dissociation can be achieved at low pressure and ambient temperature on a Si(111)-7x7 surface. Our results suggest that the low energy collision of N2 with the surface could promote an electron-transfer to the p*-antibonding orbitals of N2 that weaken the N-N bond. This would lead to the cleavage of N2 triple bond on the surface, resulting in a Si3N interface through a facile collisional dissociation. Our results could be relevant of interest in the fine comprehension of the preliminary steps of the growth of silicon nitride, which is extremely important for microelectronics. The investigation of the ability of Si(111)-7x7 for an efficient synthesis of ammonia is currently investigated.