Answer:
endothermic reactions
Step-by-step explanation:
Endothermic reactions are those reactions that absorbs heat from the surroundings as opposed to the exothermic reaction that releases heat energy. This heat absorption that characterizes endothermic reactions causes the surrounding to be cool.
However, in an endothermic reaction, more energy is needed to be absorbed in order to break the bonds of the reactants to form products, hence, making the activation energy of endothermic reactions HIGHER.