As the atomic number Z increases, is the Hartree-Fock approximation getting better and better, or worse and worse?

Why is radioactive decay measured in half-life instead of the full time?

Nuclear Mass and stability. plotting the $Ag$$-109$ Mass parabola putting the Atomic number on the $x-$axis and the Mass of the nuclei on the $y-$axis (calculated as $M=Z{m}_p+(A-Z)m_n-B$).
Noticed that even if the $Ag-109(Z=47)$ is the stable element the minimum of the parabola is on $Z=48$. Is that possible?

How can we use the half-life of Carbon-14 to date things?

What is the half-life of Uranium-238?

What is the length of decay of carbon-14?

Calculating energy released in nuclear fission
Consider the neutron induced fission $\text{U-235}+n\to \cdots \to \text{La-139}+\text{Mo-95}+2n$, where $\dots$ denotes intermediate decay steps.
I want to calculate the released energy from this fission. One way would be to calculate the difference of the binding-energies ($B$):
$\mathrm{\Delta }E=B(139,57)+B(95,42)-B(235,92)\approx 202,3\mathrm{M}\mathrm{e}\mathrm{V}$
(Btw. I didn't use the binding energies from a semi-empirical binding energy formula but calculated them directly via mass defect).
Another way is:
$\mathrm{\Delta }E=(m(\text{U-235})+m_{\text{Neutron}}-m(\text{Mo-95})-m(\text{La-139})-2m_{\text{Neutron}})c^2\approx 211,3\mathrm{M}\mathrm{e}\mathrm{V}$
Which one gives the correct result? Why?
You notice that $57+42\ne 92$, if that was the case, it would be equal, but I don't clearly see where the difference physically comes from and what to add or subtract (and why) from to the first or from the second term to get the other result. How to make this clear?
A slightly other point of view: What different questions do both calculations answer?

I was curious if antimatter could undergo nuclear fission/fusion with other antimatter. It makes sense, I was wondering if it would work?