The diagram shows the potential energy changes for a reaction pathway. A curve line graph is shown. The y axis of the graph has the title Potential Energy. The x axis of the graph has the title Reaction Pathway. The curve begins at a lower level and ends at a slightly higher level. A vertical line labeled A, starts from the x axis till the beginning of the graph line. A vertical line labeled B starts from the x axis and continues till the peak of the graph. Another vertical line labeled C is shown from the x axis till the point where the curve ends.

Part 1: Does the diagram illustrate an endothermic or an exothermic reaction? Give reasons in support of your answer.

Part 2: Describe how you can determine the total change in enthalpy and activation energy from the diagram and if each is positive or negative.