# What is the relation between bond energy and stability?

My book has two confusing statements about bond energy:

The most stable bond is the bond with the highest bond energy.

A system with low energy is a stable system. Thus, a bond is formed when electron energy level is the lowest.

So, does high energy means more stability or less stability?

• Bond energy is shows how much lower is energy of the compound. Apr 7, 2018 at 14:44
• “Bond energy” is the same as bond dissociation energy — the amount of energy to break the bond. So, if adding all the 'bond energies' of a molecule gives the highest number, it requires the most energy to break, and therefore is the most stable. Jun 1, 2022 at 22:09

Look at it in this way. Consider the energy to break a bond to be arbitrarily assumed to be at $$\pu{0 J/mol}$$. Now, there are two bonds, $$\ce{A-B}$$ and $$\ce{C-D}$$. Let's say they have energies of $$\pu{-242 kJ/mol}$$ and $$\pu{-378 kJ/mol}$$. Clearly, the $$\ce{C-D}$$ bond has the lower energy.
Now, you can say that a stronger bond needs more energy to break it. So, this means that you need to supply $$\pu{242 kJ/mol}$$ of energy to break $$\ce{A-B}$$ and $$\pu{378 kJ/mol}$$ of energy to break $$\ce{C-D}$$. You can definitely see that $$\ce{C-D}$$ needs more energy to break it, and to bring the energy to $$\pu{ 0 J/mol}$$.