I Do Stars Fuse Elements Heavier Than Iron Before Imploding?

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Stars do not fuse elements heavier than iron because it is not energetically favorable; instead, fusion beyond iron absorbs energy rather than producing it. Black holes are not simply stars that have stopped fusing elements; they result from the collapse of massive stars after a supernova event. Heavy elements are produced during supernovae, but the fusion process ceases to be self-sustaining at iron. Iron does not produce energy during fusion due to the binding energy per nucleon trend, where heavier elements require energy to fuse rather than releasing it. Understanding stellar evolution requires knowledge of nuclear processes such as fusion, fission, and decay.
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Anything beyond iron?
I know black holes are stars that fuse together elements until they reach iron which doesn't radiate energy to counterbalance the gravity, but do any stars fuse elements heavier than iron that would once again give off energy prior to it imploding?

By the way, why doesn't iron creation create radiation?
 
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LightningInAJar said:
Summary:: Anything beyond iron?

I know black holes are stars that fuse together elements until they reach iron which doesn't radiate energy to counterbalance the gravity
This is incorrect. A black hole is a region of spacetime from which light cannot escape.

Regarding fusing of elements: Iron has the highest binding energy per nucleon. It would not be energetically favorable to fusion it to heavier elements.
 
As Orodruin says, a black hole is not just a star that's stopped fusing. That leads to a (super)nova and some larger stars collapse into black holes, but a black hole is very different from a star.

All sorts of heavy elements get produced in supernovae. I'm sure they get produced in tiny quantities in during normal operation, but it's an energy absorber not a producer so the process isn't self-sustaining. That's why you don't see iron-burning stars - it's the fusion equivalent of trying to light ashes.

As to why iron doesn't produce energy, the binding energy per nucleon changes as the atomic mass rises. It first increases, meaning that one helium atom needs slightly more energy to separate it into four nucleons than two deuterium atoms do. So two deuterium atoms combining into one helium leaves a bit of energy over.

But that stops at iron, and then the trend reverses. Very heavy elements need less energy to separate into components than smaller ones, so combining smaller atoms costs energy. Splitting large atoms into smaller ones (down to iron) releases energy - which is nuclear fission.

The underlying reason for the differences in binding energy is the balance between the strong force holding the nucleus together and increasing amounts of electrostatic repulsion between the increasing number of protons.
 
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LightningInAJar said:
Summary:: Anything beyond iron?

I know black holes are stars that fuse together elements until they reach iron which doesn't radiate energy to counterbalance the gravity
You have a very bad habit of starting threads with "I know that" followed by something totally false. These are bad starts. Please stop this.
 
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LightningInAJar said:
Summary:: Anything beyond iron?

By the way, why doesn't iron creation create radiation?
It does in some cases, for example the decay of Ni-56 to Fe-56.

Before you can understand the nuclear reactions involved in stellar evolution and collapse you will need a better understanding of the most important nuclear processes: fusion, fission, alpha and beta decay - you might start by searching for "binding energy curve" and "decay chain".

As this thread is based on a misunderstanding that has been addressed, it is closed.
 
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