Energy is neither created nor destroyed in a chemical reactions.

[anzgurl]

Energy is neither created nor destroyed in a chemical reactions. Explain where the energy released by the reactions comes from.

 

[Astronuc]

Chemical energy exists in the bonds between atoms.

For example, consider a chemical reaction 2 H₂ + O₂ -> H₂O. The bonds of H and O molecules break and reform to H-O bonds, and energy is released. This is an example of combustion - and this reaction is responsible for propelling the space shuttle into orbit.