# Nuclear Chemistry

• +Minkie+

#### +Minkie+

Is it true an Iron nucleus requires the most amount of energy to hold it together?

I would have thought it would be the larger the nucleus the more energy is required to hold it toghether.

## Answers and Replies

Is it true an Iron nucleus requires the most amount of energy to hold it together?
Per nucleon, yes.

I would have thought it would be the larger the nucleus the more energy is required to hold it toghether.
The total binding energy increases with the nuclear mass, but the binding energy per nucleon hits a maximum at Fe.

So a heavier nucleus, not too much heavier, may have less overall binding energy than Fe?

Say Nickel compared to Iron?

So a heavier nucleus, not too much heavier, may have less overall binding energy than Fe?

Say Nickel compared to Iron?
It's possible, but I don't know the actual numbers.

PS: Fe-56 has the highest BE per nucleon among naturally occurring isotopes; I believe one of the artificial isotopes of Ni has a higher value.

Last edited:
What I'm getting at is if that were true wouldn't it prove E=MC^2 wrong?
As the Fe nucleus would have more energy but less mass than the nickel nucleus.

What I'm getting at is if that were true wouldn't it prove E=MC^2 wrong?
As the Fe nucleus would have more energy but less mass than the nickel nucleus.
No, it would not. The binding energy is not the same as the rest energy of the nucleus. The binding energy is related to the mass defect, not the total nuclear mass. The greater the mass defect, the greater the total binding energy.

If you think there's something that proves E=mc^2 wrong, then you've either got incorrect data, or you're applying an incorrect reasoning. In this case, it is the latter.

I see how my thinking was wrong, it was worth a try though.
Imagine proving Einstein wrong