30. How much energy is released in the decay of radium-223 to radon-219? { }_{88}^{223} \mathrm{Ra} \rightarrow{ }_{86}{ }^{219} \mathrm{Rn}+{ }_{2}^{4} \mathrm{He} m\left({ }_{2}^{4} \mathrm{He}\right)=4.002603250 \mathrm{u} m\left(\begin{array}{c} 219 \\ 86

\end{array} \mathrm{n}\right)=219.009474832 \mathrm{u} m\left(\begin{array}{c} 223 \\ 88 \end{array} \mathrm{Ra}\right)=223.018497140 \mathrm{u}