Why does an endothermic reaction require a greater activation energy than an exothermic one?​

Exothermic reactions, however, have a lower activation energy compared to the reverse endothermic reaction. This is because there is a net energy release from an exothermic reaction because the products have less energy than the reactants.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

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