# Nuclear Binding Energy: Is my understanding correct?

• B

## Summary:

I want to write a student article specially for those who don't have a background in nuclear physics. I've been suggested to share my basic understanding & ask if they're correct.
I would be grateful if anyone could explain where my mistakes are:
(Please note that diagrams are designed just to give a simple imagination of the article & make it more understandable; they do NOT correspond precise information.)
The binding energy of a nucleus is the energy of the strong force, minus the disruptive energy due to the Coulomb force. Thus, to illustrate the curve of binding energy per nucleon, we can combine both of the diagrams above:

Analyzing this diagram is very important for studying nuclear reactions. Here is some fundamental information:

For the lightest nuclei, binding energy per nucleon grows rapidly; because the attractive strong force grows noticeably due to the small size of nuclei, but the repelling Coulomb force is much less due to small atomic number.

As nuclei get heavier, the strong force starts to face a nuclear size limit, but the electrostatic force is growing as slowly as before. So their binding energy per nucleon grows more and more slowly; reaching its peak at iron and nickel.

By the time copper (Z=29) is reached, this disruptive effect becomes steadily more significant, and the attractive force also increases, but at a slower rate. Thus nuclear binding energy per nucleon starts to decrease slowly.

Finally, for the heaviest nuclei, the electric repulsion becomes noticeably high, while the strong nuclear force per nucleon almost hasn't changed. So the binding energy per nucleon falls at its rapidest rate. But note that even for the heaviest nuclei, binding energy is ALWAYS a positive number.
In general, nuclei smaller than iron are called 'light elements', and larger ones are called 'heavy elements'.

According to the right diagram, helium-4 nucleus is so tightly bound (in proportion to its small size) that it is commonly treated as a single quantum mechanical particle in nuclear physics, namely, the alpha (α) particle.

References:
https://en.wikipedia.org/wiki/Nuclear_binding_energyhttps://en.wikipedia.org/wiki/Nuclear_fusion

Last edited by a moderator: