@X@user.full_name@X@ @GMU: ACS-Radioactive substances decay…
@X@user.full_name@X@ @GMU: ACS-Radioactive substances decay by first-order kinetics. How many years would be required for a sample containing americium-95 to decrease to 40.15% of its initial activity? The half-life of americium-95 is 4.58e2 years.