15. The bonds between atoms store ______________________, When the bonds break the energy (in the form of light or heat) can be released.

Answer 1

Hi Brigham F.,

Contrary to what your instructor is suggesting in this fill-in-the-blank question, chemical bonds do not store chemical energy, except relative to other possible compounds that the same set of atoms could alternatively be making. An individual bond always represents an energy deficit relative to the particular atoms apart from each other (unbonded). That is what makes compounds stable at all!

But let's explore the idea. Suppose you had a string of bonded atoms O-P-O-P-O-P-O , such as you do in adenosine triphosphate, or ATP, your body's energy currency for about all of its synthesis reactions. IF you were to break off the final O-P-O (there are also other O's on the P's, I've simplified) group, that breakage required a little energy to do. But then, the O-P-O goes out into the surrounding medium, and a good deal of energy is set free which your body can cleverly couple into doing good reactions so that you can live. Because there's a good deal of energy liberated overall in the reaction, those bonds in ATP are termed "high energy". Even though they don't have positive "energy" in, inherently -- they are actually little energy "pits" (negative energy) relative to the flat energy "plane" of separated atoms!

You can translate this, perhaps, into being in a little depression on top of a tall hill, on your mountain bike. Sure, eventually you will be descending fast (perhaps too fast?) (liberating energy in a reaction, making products, heat, light, etc.), but first you have to push up out of the little depression (the bond you are in).

--Cheers, --Mr. d.