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Appendix B Select Radioactive Isotopes

Decay modes are $latex \alpha $, $latex \beta ^{-}$, $latex \beta ^{+}$, electron capture (EC) and isomeric transition (IT). EC results in the same daughter nucleus as would $latex \beta ^{+}$ decay. IT is a transition from a metastable excited state. Energies for $latex \beta ^{\pm}$ decays are the maxima; average energies are roughly one-half the maxima.

Isotope t 1/2 DecayMode(s) Energy(MeV) Percent $latex \gamma $-Ray Energy(MeV) Percent
$latex ^{3} \textbf{H}$ 12.33 y $latex \beta ^{-}$­ 0.0186 100%
$latex ^{14} \textbf{C}$ 5730 y $latex \beta ^{-}$ 0.156 100%
$latex ^{13} \textbf{N}$ 9.96 min $latex \beta ^{+}$ 1.20 100%
$latex ^{22} \textbf{Na}$ 2.602 y $latex \beta ^{+}$ 0.55 90% $latex \gamma $ 1.27 100%
$latex ^{32} \textbf{P} $ 14.28 d $latex \beta ^{-}$ 1.71 100%
$latex ^{35} \textbf{S}$ 87.4 d $latex \beta ^{-}$­ 0.167 100%
$latex ^{36} \textbf{Cl} $ $latex 3.00 \times 10^5 \text{y}$ $latex \beta ^{-}$ 0.710 100%
$latex ^{40} \textbf{K} $ $latex 1.28 \times 10^9 \text{y} $ $latex \beta ^{-} $ 1.31 89%
$latex ^{43} \textbf{K} $ 22.3 h $latex \beta ^{-} $ 0.827 87% $latex \gamma \;\text{s} $ 0.373 87%
0.618 87%
$latex ^{45} \textbf{Ca}$ 165 d $latex \beta ^{-} $­ 0.257 100%
$latex ^{51} \textbf{Cr} $ 27.70 d EC $latex \gamma $ 0.320 10%
$latex ^{52} \textbf{Mn}$ 5.59d $latex \beta ^{+}$ 3.69 28% $latex \gamma \;\text{s} $ 1.33 28%
1.43 28%
$latex ^{52} \textbf{Fe}$ 8.27 h $latex \beta ^{+}$ 1.80 43% 0.169 43%
0.378 43%
$latex ^{59} \textbf{Fe}$ 44.6 d $latex \beta ^{-}$ 0.273 45% $latex \gamma \;\text{s} $ 1.10 57%
0.466 55% 1.29 43%
$latex ^{60} \textbf{Co}$ 5.271 y $latex \beta ^{-}$­ 0.318 100% $latex \gamma \;\text{s} $ 1.17 100%
1.33 100%
$latex ^{65} \textbf{Zn}$ 244.1 d EC $latex \gamma $ 1.12 51%
$latex ^{67} \textbf{Ga}$ 78.3 h EC $latex \gamma \;\text{s} $ 0.0933 70%
0.185 35%
0.300 19%
others
$latex ^{75} \textbf{Se}$ 118.5 d EC $latex \gamma \;\text{s} $ 0.121 20%
0.136 65%
0.265 68%
0.280 20%
others
$latex ^{86} \textbf{Rb}$ 18.8 d $latex \beta ^{-}$ 0.69 9% $latex \gamma $ 1.08 9%
1.77 91%
$latex ^{85} \textbf{Sr}$ 64.8 d EC $latex \gamma $ 0.514 100%
$latex ^{90} \textbf{Sr}$ 28.8 y $latex \beta ^{-}$­ 0.546 100%
$latex ^{90} \textbf{Y}$ 64.1 h $latex \beta ^{-}$­ 2.28 100%
$latex ^{99m} \textbf{Tc}$ 6.02 h IT $latex \gamma $ 0.142 100%
$latex ^{113m} \textbf{In}$ 99.5 min IT $latex \gamma $ 0.392 100%
$latex ^{123} \textbf{I}$ 13.0 h EC $latex \gamma $ 0.159 $latex \approx 100 \% $
$latex ^{131} \textbf{I}$ 8.040 d $latex \beta ^{-}$ 0.248 7% $latex \gamma \;\text{s} $ 0.364 85%
0.607 93% others
others
$latex ^{129} \textbf{Cs}$ 32.3 h EC $latex \gamma \;\text{s} $ 0.0400 35%
0.372 32%
0.411 25%
others
$latex ^{137} \textbf{Cs}$ 30.17 y $latex \beta ^{-} \;\text{s}$­ 0.511 95% $latex \gamma $ 0.662 95%
1.17 5%
$latex ^{140} \textbf{Ba}$ 12.79 d $latex \beta ^{-}$ 1.035 $latex \approx 100 \& $ $latex \gamma \;\text{s} $ 0.030 25%
0.044 65%
0.537 24%
others
$latex ^{198} \textbf{Au}$ 2.696 d $latex \beta ^{-}$­ 1.161 $latex \approx 100 \% $ $latex \gamma $ 0.412 $latex \approx 100 \% $
$latex ^{197} \textbf{Hg}$ 64.1 h EC $latex \gamma $ 0.0733 100%
$latex ^{210} \textbf{Po}$ 138.38 d $latex \alpha $ 5.41 100%
$latex ^{226} \textbf{Ra}$ $latex 1.60 \times 10^3 \text{y}$ $latex \alpha \;\text{s} $ 4.68 5% $latex \gamma $ 0.186 100%
4.87 95%
$latex ^{235} \textbf{U}$ $latex 7.038 \times 10^8 \text{y}$ $latex \alpha $ 4.68 $latex \approx 100 \% $ $latex \gamma \;\text{s} $ numerous <0.400%
$latex ^{238} \textbf{U}$ $latex 4.468 \times 10^9 \text{y}$ $latex \alpha \;\text{s} $ 4.22 23% $latex \gamma $ 0.050 23%
4.27 77%
$latex ^{237} \textbf{Np}$ $latex 2.14 \times 10^6 \text{y}$ $latex \alpha \;\text{s} $ numerous $latex \gamma \;\text{s} $ numerous <0.250%
4.96 (max.)
$latex ^{239} \textbf{Pu}$ $latex 2.41 \times 10^4 \text{y}$ $latex \alpha \;\text{s} $ 5.19 11% $latex \gamma \;\text{s} $ $latex 7.5 \times 10^{-5} $ 73%
5.23 15% 0.013 15%
5.24 73% 0.052 10%
others
$latex ^{243} \textbf{Am}$ $latex 7.37 \times 10^3 \text{y}$ $latex \alpha \;\text{s} $ Max. 5.44 $latex \gamma \;\text{s} $ 0.075
5.37 88% others
5.32 11%
others
Table 2. Selected Radioactive Isotopes

 

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Appendix B Select Radioactive Isotopes by OpenStax is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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