What kind of energy is stored in the bond between atoms?

Answer 1

It is a wide-spread misconception among the public, students, and sadly among educators that chemical bonds storeenergy. Nothing can be further from the truth.

Colloquially, we speak of chemical compounds as being sources of energy. For example, hydrocarbons (gasoline) are said to be a source of energy for our cars, and carbohydrates (sugar) are said to be a source of energy for our bodies. This common use of language leads to seriously flawed assumptions about the nature and energy of chemical bonds in molecules.

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Take water (H2O), for example. How much energy is stored (i.e.: can be released chemically) in the bonds between the hydrogen and oxygen atoms in the H2O molecule? The answer is ZERO - none - nothing. There is no usable energy in those chemical bonds.

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But, if we were to apply energy to water in the form of electrical hydrolysis, we can separate the hydrogen and oxygen into 2H2 and O2 molecules. Now let those separated hydrogen and oxygen gas molecules freely mix in a chamber, and now ask: how much energy is stored in that H2 and O2 mixture? Lots! Just one little spark in a kilogram (2.2 pounds) of hydrogen gas mixed with O2 will release 148 MJ/Kg - enough energy to kill. That is the same amount of energy as 1,480,000 light bulbs burning at 100 Watts for 1 second!

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So there is no energy stored in the chemical bonds of the water molecule at all. Similarly, there is no energy stored inside the chemical bonds of the H2 and O2 molecules that combined to make the water molecules. The potential energy arises when free H2 and O2 gasses are allowed to coalesce. The same is true of hydrocarbons and carbohydrates. They do not store bond energy inside their molecules. But when they are in proximity of other molecules that they can react with (usually oxygen), that mixture of compounds itself is a source of potential (stored) chemical energy.

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The closest (albeit crude) analogy to chemical potential energy in the physical world is magnets. Imagine two small magnets sitting on a table top. They are too far apart to overcome the surface friction, so they just sit there. Add a little energy by moving them closer to each other, and suddenly the attractive magnetic force will overcome the resistive friction force, and in a flash, potential magnetic energy converts into kinetic energy, and the magnets move toward each other and snap firmly in place. Once the magnets are paired against each other, there is no more energy stored in that system - all the available magnetic potential energy has all been converted to kinetic energy.

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Similarly, once chemical bonds are formed, there is no energy stored in the bonds of the resulting compounds. The potential chemical energy that did exist before the reaction was released (usually as heat) as part of the chemical reaction. Stored chemical energy exists before chemical bonds are created - before the H2 and O2 combine to form water. Once the hydrogen and oxygen combine to create water, there is no energy stored in the resulting chemical bonds.

In the same way, a hydrocarbon or carbohydrate molecule has absolutely no potential (stored) chemical energy in the bonds between its atoms before it burns with oxygen. The potential (stored) chemical energy that does exist arises because the fuel is in close proximity with the oxygen. The chemical reaction that combines the fuel with the oxygen converts the potential chemical energy into usable energy.

Answer 2

chemical energy is stored in the bonds between atoms

Answer 3

chemical energy is the energy stored in bonds between atoms.

Answer 4

I think you're looking for 'chemical energy,' as opposed to electrical energy, or mechanical energy, or kinetic energy, etc.

Answer 5

Chemical energy

Answer 6

Chemical energy

Answer 7

Chemical Energy.

Answer 8

potential

Answer 9

kinetic