\(\lambda = \frac{{\ln 2}}{T} = \frac{{\ln 2}}{{8,02 \cdot 24 \cdot 60 \cdot 60}} \approx {10^{ - 6}}\;{{\rm{s}}^{ - 1}} \Rightarrow \)a) Sai

\(_{53}^{131}I \to _{ - 1}^0e + _{54}^{131}Xe \Rightarrow \)b) Đúng

\(n = \frac{m}{M} = \frac{{0,806 \cdot {{10}^{ - 6}}}}{{131}} \approx 6,153 \cdot {10^{ - 9}}\;{\rm{mol}}\)

\({N_0} = n{N_A} = 6,153 \cdot {10^{ - 9}} \cdot 6,02 \cdot {10^{23}} \approx 3,704 \cdot {10^{15}}\)

\(\Delta N = {N_0}\left( {1 - {2^{\frac{{ - t}}{T}}}} \right) = 3,704 \cdot {10^{15}} \cdot \left( {1 - {2^{\frac{{ - 4,01}}{{8,02}}}}} \right) \approx 1,085 \cdot {10^{15}}\)

\(Q = \Delta NE = 1,085 \cdot {10^{15}} \cdot 0,606 \cdot 1,6 \cdot {10^{ - 13}} \approx 105J \Rightarrow \)c) Sai

\(H = \lambda N = \frac{{\ln 2}}{T} \cdot {N_0} \cdot {2^{\frac{{ - t}}{T}}} \Rightarrow 37 \cdot {10^6} = \frac{{\ln 2}}{{8,02 \cdot 24 \cdot 60 \cdot 60}} \cdot 3,704 \cdot {10^{15}} \cdot {2^{\frac{{ - t}}{{8,02}}}} \Rightarrow t \approx 53{\rm{ ng\`a y }} \Rightarrow \)d) Sai

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