system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: As Francium is the most unstable element, how much more energy will it generate if it is split compared to, let's say Uranium?
gpt
The half-life of an element doesn't really say anything about the energy release per-atom when fission occurs.

Fr223 to Ra223 produces 1.149 MeV of energy

Boring U238 to Th234 produces 4.270 MeV of energy, but only once every 5 billion years.

Shorter half-life isotopes release more heat overall because the decay is so much faster, but all this really does is make the material difficult to process and handle.

The heat buildup is often sufficient to melt or vaporize samples, rendering them useless.