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My picture of fission is that the nuclear force is the centripetal force and the electrostatic is the centrifugal one and when some energy helps the electrostatic force the nucleus reacts with fission.What confuses me is the increment of binding energy as there are more nucleons in the core. Is that like every nucleon gives some energy to the other one when the two are binded together and so everyone can attract some other nucleon with more force(like bar magnets) but after iron atom there is so much electrostatic force to subtract from this centripetal force so the total binding energy is weaker?

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Is that like every nucleon gives some energy to the other one when the two are binded together and so everyone can attract some other nucleon with more force(like bar magnets) but after iron atom there is so much electrostatic force to subtract from this centripetal force so the total binding energy is weaker?

Yes, this is basically the right idea. The strong nuclear force has a short range, so in a nucleus containing $A$ nucleons, the strong nuclear force contributes to the binding energy in proportion to $A$ rather than $A^2$. As a simple classical toy model, if you imagine the nucleus as a cluster of grapes, each grape might have, say, 6 neighbors, so the number of attractive interactions is $6A$.

The electrical force is long-range, so the number of pairs of particles interacting goes like $Z^2$. For large $A$ and $Z$, this grows faster than the nuclear contribution to the binding energy.

To see this more quantitatively, try graphing the liquid drop energy in a utility like desmos. Put in $Z\approx A/2$, and divide the whole thing by $A$ so that you're graphing the binding energy per nucleon rather than the total binding energy. You will see that it maxes out at around $A=50$, which is basically iron.

My picture of fission is that the nuclear force is the centripetal force and the electrostatic is the centrifugal one and when some energy helps the electrostatic force the nucleus reacts with fission.

The words "centripetal" and "centrifugal" have connotations of circular motion, which are not correct here. And binding energies relate to thing like beta decay and fusion as well, not just fission.

Does more binding energy between nucleons in different elements as they have more nucleons mean the nuclear force between them is stronger?

It's not really clear what you mean by this or how this relates to your question. In the model described above, the strength of the nuclear binding between any pair of nucleons, if they're within range, is constant, not varying.

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