Answer:
The reaction in the cold pack is an endothermic reaction
Explanation:
An endothermic reaction is a reaction that absorbs energy (heat) from the surrounding to supply the required energy of activation that allows the occurrence of the reaction
Therefore, when a reaction is endothermic, it boundary or the system where the reaction is occurring feels cold to touch
Hence, the reaction in the cold pack is an endothermic reaction.
I think its called refraction
I believe it it a chemical reaction...hope this helps and you make a good grade :