answer: enthalpy
explanation:
for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.
![\delta h=e_p-e_r](/tex.php?f=\delta h=e_p-e_r)
= enthaply
= energy of products
= energy of reactants
as
, thus
comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.