Step-by-step explanation:
Exothermic reactions are those reactions in which heat is released.
Reactants→products+heat
For example, formation of ammonia from nitrogen and hydrogen is an exothermic reaction.
N2(g)+3H2(g)→2NH3(g)+92.2kJ
Endothermic reactions are those reactions in which heat is absorbed.
Reactants+heat→products
For example, dissociation of ammonia into nitrogen and hydrogen is an endothermic reaction.
2NH3 (g)+92.2kJ→
N2(g)+3H2(g)