Starting from the molecular collision theory, the goals of this study are the simulation and visualization of some processes related to gases transport properties and gaseous fuel combustion, like: formation of Maxwell distribution function, diffusion, thermal diffusion, heat conductivity, heat transfer to the walls, spark ignition, autoignition, wall ignition, laminar flame propagation and two wall quenching.The simulation program replaces the molecules with a certain number of spheres (100-2700). Each specie is simulated with a determined type of sphere characterized by mass, speed, diameter and a specific color for the identification on the screen. The spheres moves inside a two-dimensional space. The collisions between spheres are elastic. The activation energy condition must be achieved during a collision involving two molecules in order to have chemical reaction. The complete oxidation of fuel sphere occurs during a multiple step process; the consumption of oxidation capability of oxygen sphere needs multiple stages. Energy exchange between walls and spheres occurs when we consider that the spheres holder has no adiabatic walls.During chemical reactions, spheres change their color, so all the above mentioned processes are visualized on the screen. The program succeed to highlight the influences on processes of a few parameters: mixture temperature, wall temperature, spark energy, mixture quality, fuel type. Also, the importance of the radicals and chain branching reactions are underlined.