# What type of chemical reactions only occur if there is an input of energy?

Mar 27, 2017

In fact most chemical reactions require energy input (i.e. $\text{energy of activation}$) to make them go..........
But given the context of the question, clearly they are looking for the answer of $\text{endothermic reactions}$, in which the enthalpy of the PRODUCTS is greater than the enthalpy of the reactants:
$\text{Reactants"+Deltararr"Products}$