Answer:
splitting a gas molecule
Explanation:
Endothermic reactions can be regarded as chemical reactions whereby there is absorbing of heat energy by the reactant from the surroundings when forming the products. Cooling effect is created because the reaction will lower the surrounding temperature after it must have absorbed heat. In endothermic reaction, the standard enthalpy change ΔH⚬ is positive. For instance when gas molecules is splitter heat energy is absorbed.
