Answer: Option (d) is the correct answer.
Explanation:
A chemical reaction in which heat is released by the reactants is known as an exothermic reaction.
For example, [tex]A + B \rightarrow AB + Heat[/tex]
As energy is released, hence total energy of products is less than the total energy of reactants in an exothermic reaction.
On the other hand, a chemical reaction in which heat is absorbed by reactant molecules is known as an endothermic reaction.
For example, [tex]A + B + Heat\rightarrow AB + Heat[/tex]
As energy is absorbed, hence total energy of reactants is less than the total energy of products in an endothermic reaction.
Thus, we can conclude that when you crush a first-aid pack for an injured athlete and the pack gets cold, a chemical change has occurred, with energy being absorbed.
