And the transition state is this transient molecule, transient stage that exists between the reactants and our products. Now, what exactly will the transition state look like when we go from the reactants to the products? Well, we have a single elementary, a single step elementary reaction in which on the reactants side we have a bond between A and B. And on the product side, we have a bond between B and C. And what that implies is to actually go from the reactants to the products, we have to break the bond between A and B and we have to form the bond between B and C. So in that transition stage, what we're going to see is a bond breaking between A and B. So B will begin to move away from A and because the electron density will basically move away, that bond between A and B will begin to break. And that can be described by using a dashed line.