**Practice Problem 6**

The most abundant isotope of uranium is ^{238}U; 99.276% of the atoms in a
sample of uranium are ^{238}U. Calculate the activity of the ^{238}U
in 1 L of a 1.00 *M* solution of the uranyl ion, UO_{2}^{2+}.
Assume that the rate constant for the decay of this isotope is 4.87 x 10^{-18}
disintegrations per second.

**Answer**

79.2 mCi.