Question

try it: energy of reactions
the energy diagram on the right is an example of an...
exothermic
endothermic

Explanation:

In an exothermic reaction, the energy of products is lower than that of reactants, releasing heat. In an endothermic reaction, products have higher energy than reactants, absorbing heat. The left - hand diagram shows products with lower energy than reactants (negative $\Delta H$), an exothermic reaction. The right - hand diagram shows products with higher energy than reactants (positive $\Delta H$), an endothermic reaction.

Answer:

Left diagram: A. Exothermic
Right diagram: B. Endothermic