A $20-$gram reactor Uranium fuel pellet that has ${?}^{235}U$ enhanced to $3\%$ is

encapsulated and placed in the reactor to generate power. After the fuel pellet

has been "burned up$",$ so that only $0\mathrm{.}5\%{?}^{235}U$ remains in the pellet, it is removed

from the reactor and scheduled for reprocessing. After sitting idle for three

months, the pellet is then reprocessed. How many grams of the element Xenon

might it be possible to recover and what would be the dominant isotopes in the

recovered element? Remember that products from fission are generally neutron

rich. $($Hint: What isobars decay to "stable" Xe nuclides over $3$ months?$)$