\(H=-\dfrac{dN}{dT}=kN=3,7.10^{10}\left(Bq\right)\)
\(k=\dfrac{ln\left(2\right)}{t_{\dfrac{1}{2}}}\Rightarrow\) Số nguyên tử Ra: \(N=\dfrac{3,7.10^{10}}{0,693}.t_{\dfrac{1}{2}}\)
\(m_{Ra}=\dfrac{226.3,7.10^{10}.1590.365.24.60.60}{6,022.0,693.10^{23}}=1\left(g\right)\)