Answer: The reactant might either absorb ionization energy or release electron gain enthalpy.
Step-by-step explanation:
Activation energy is defined as the minimum amount of energy required by the reactants to form products (different compounds).
When none of the reactant molecules have absorbed the activation energy, it means that a different compound has not been formed.
The chemical properties of the element have remained the same. This can be done when an electron is lost in a chemical species or when an electron is added to a chemical species.
The energy required to release an electron from a chemical species is known as ionization energy and the energy released to add an electron to a chemical species is known as electron gain enthalpy.
Hence, the reactant might either absorb ionization energy or release electron gain enthalpy.