Answer
The percentage deviation is $~~0.73~\%$
Work Step by Step
We can find the percentage deviation for $^{239}Pu$:
$\frac{M_{app}-M}{M}~\times 100\%$
$= \frac{A~m_p-239.052 157~u}{239.052 157~u}~\times 100\%$
$= \frac{(239)(1.673\times 10^{-27}~kg)-(239.052 157)(1.660538782\times 10^{-27}~kg)}{(239.052 157)(1.660538782\times 10^{-27}~kg)}~\times 100\%$
$= 0.73~\%$
The percentage deviation is $~~0.73~\%$
