You should now be in a position to appreciate the difference between the thermodynamic feasibility of a reaction and the likelihood that it will actually proceed. Many reactions that are thermodynamically pas site do not occur at an appreciable rate because of the activation energy required for the reactants to achieve the transition state. In molecular terms, what does this mean? Drag the terms on the left to the appropriate blanks on the right to complete the sentences. One way to meet this requirement is by an input of heat, which in some cases need only be an initial, transient input Think of an example, and explain what this accomplishes in molecular terms. Drag the terms on the left to the appropriate blanks on the right to complete the sentences.