Why doesn't iron give off any energy when it is created through nuclear fusion?

[Forestman]

I know from reading that when the core from a massive star is transformed into iron through the process of nuclear fusion that the star collapses because the newly formed iron core does not put out any energy to support the weight of the star. My question is, why is iron like this when it is created? Why does it not put out any energy?

 

[malawi_glenn]

Because iron has the largest binding energy per nucleon

 

[Forestman]

Thanks malawi_glenn.

 

[malawi_glenn]

Thanks malawi_glenn.

Or, to be as specific as one can be, I think it is Ni-58 which has it, but Iron-56 is pretty close ;-)