An endothermic reaction is required to break a chemical bond right? When a bond is formed, the reaction is exothermic. So...

 

why does splitting an atom yield an highly exothermic reaction if there are no new bonds forming?

 

~ee

 

An endothermic reaction is required to break a chemical bond right? When a bond is formed, the reaction is exothermic.

 

Not quite.

 

Most chemical reactions require the breaking of bonds, before new ones can be made (if there are new ones).

But breaking of bonds alone is only the first part of the reaction.

The second part may release energy.

 

The terms exothermic and endothermic refer to the entire reaction.

 

It is the net direction of heat energy that decides.

 

So if more heat energy is evolved than needs to be input at the beginning the reaction is exothermic.

Likewise if you need to put in more heat than you get back the reaction is endothermic.

Pleae note that the terms refer to specifically to heat energy.

 

Does this help?

Edited September 27, 201312 yr by studiot

Is "splitting an atom" a reference to fission, or the breaking of chemical bonds? These are two very different processes.