Simulation of a reaction is a chemical reaction modeling or demonstration tool, using various software to better understand the molecular structure and the physical and chemical properties of the molecule. Here the actual reaction is N2 + 3H2 -----> 2NH3. In the simulation reactions, the nitrogen and hydrogen molecules in the actual reaction are described by different colored circles or dots and the bonds are produced using a single, double or triple line that touches each molecule and gives an appearance like the reactants and the products' ball and stick model. Example: Molecule of nitrogen as o---triple line---o. A molecule of hydrogen as O———O. Chemical symbols such as N and H are expressed in Actual Chemical Reaction, N2 and H2 and the bonds are represented by single, double or triple lines that do not impact the atoms in the molecule as follows: Nitrogen Molecule: N -triple Bond- N. Hydrogen Molecule: H - H. Hope it helps ya