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

Selected Radioactive Isotopes
Isotope t1/2 DecayMode(s) Energy(MeV) Percent \(\gamma \)-Ray Energy(MeV) Percent
\({\text{}}^{3}\text{H}\) 12.33 y \({\beta }^{-}\) ­ 0.0186 100%
\({\text{}}^{14}\text{C}\) 5730 y \({\beta }^{-}\) 0.156 100%
\({\text{}}^{13}\text{N}\) 9.96 min \({\beta }^{+}\) 1.20 100%
\({\text{}}^{22}\text{Na}\) 2.602 y \({\beta }^{+}\) 0.55 90% \(\gamma \) 1.27 100%
\({\text{}}^{32}\text{P}\) 14.28 d \({\beta }^{-}\) 1.71 100%
\({\text{}}^{35}\text{S}\) 87.4 d \({\beta }^{-}\) ­ 0.167 100%
\({\text{}}^{36}\text{Cl}\) \(3\text{.}\text{00}×{\text{10}}^{5}\text{y}\) \({\beta }^{-}\) 0.710 100%
\({\text{}}^{40}\text{K}\) \(1\text{.}\text{28}×{\text{10}}^{9}\text{y}\) \({\beta }^{-}\) 1.31 89%
\({\text{}}^{43}\text{K}\) 22.3 h \({\beta }^{-}\) 0.827 87% \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 0.373 87%
0.618 87%
\({\text{}}^{45}\text{Ca}\) 165 d \({\beta }^{-}\) ­ 0.257 100%
\({\text{}}^{51}\text{Cr}\) 27.70 d EC \(\gamma \) 0.320 10%
\({\text{}}^{52}\text{Mn}\) 5.59d \({\beta }^{+}\) 3.69 28% \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 1.33 28%
1.43 28%
\({\text{}}^{52}\text{Fe}\) 8.27 h \({\beta }^{+}\) 1.80 43% 0.169 43%
0.378 43%
\({\text{}}^{59}\text{Fe}\) 44.6 d \({\beta }^{-}\text{s}\) 0.273 45% \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 1.10 57%
0.466 55% 1.29 43%
\({\text{}}^{60}\text{Co}\) 5.271 y \({\beta }^{-}\) ­ 0.318 100% \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 1.17 100%
1.33 100%
\({\text{}}^{65}\text{Zn}\) 244.1 d EC \(\gamma \) 1.12 51%
\({\text{}}^{67}\text{Ga}\) 78.3 h EC \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 0.0933 70%
0.185 35%
0.300 19%
others
\({\text{}}^{75}\text{Se}\) 118.5 d EC \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 0.121 20%
0.136 65%
0.265 68%
0.280 20%
others
\({\text{}}^{86}\text{Rb}\) 18.8 d \({\beta }^{-}\text{s}\) 0.69 9% \(\gamma \) 1.08 9%
1.77 91%
\({\text{}}^{85}\text{Sr}\) 64.8 d EC \(\gamma \) 0.514 100%
\({\text{}}^{90}\text{Sr}\) 28.8 y \({\beta }^{-}\) ­ 0.546 100%
\({\text{}}^{90}\text{Y}\) 64.1 h \({\beta }^{-}\) ­ 2.28 100%
\({\text{}}^{99m}\text{Tc}\) 6.02 h IT \(\gamma \) 0.142 100%
\({\text{}}^{113m}\text{In}\) 99.5 min IT \(\gamma \) 0.392 100%
\({\text{}}^{123}\text{I}\) 13.0 h EC \(\gamma \) 0.159 \(\text{≈100%}\text{}\)
\({\text{}}^{131}\text{I}\) 8.040 d \({\beta }^{-}\text{s}\) 0.248 7% \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 0.364 85%
0.607 93% others
others
\({\text{}}^{129}\text{Cs}\) 32.3 h EC \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 0.0400 35%
0.372 32%
0.411 25%
others
\({\text{}}^{137}\text{Cs}\) 30.17 y \({\beta }^{-}\text{s}\) ­ 0.511 95% \(\gamma \) 0.662 95%
1.17 5%
\({\text{}}^{140}\text{Ba}\) 12.79 d \({\beta }^{-}\) 1.035 \(\text{≈100%}\text{}\) \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 0.030 25%
0.044 65%
0.537 24%
others
\({\text{}}^{198}\text{Au}\) 2.696 d \({\beta }^{-}\) ­ 1.161 \(\text{≈100%}\text{}\) \(\gamma \) 0.412 \(\text{≈100%}\text{}\)
\({\text{}}^{197}\text{Hg}\) 64.1 h EC \(\gamma \) 0.0733 100%
\({\text{}}^{210}\text{Po}\) 138.38 d \(\alpha \) 5.41 100%
\({\text{}}^{226}\text{Ra}\) \(1\text{.}\text{60}×{\text{10}}^{3}\text{y}\) \(\alpha \text{s}\) 4.68 5% \(\gamma \) 0.186 100%
4.87 95%
\({\text{}}^{235}\text{U}\) \(7\text{.}\text{038}×{\text{10}}^{8}\text{y}\) \(\alpha \) 4.68 \(\text{≈100%}\text{}\) \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) numerous <0.400%
\({\text{}}^{238}\text{U}\) \(4\text{.}\text{468}×{\text{10}}^{9}\text{y}\) \(\alpha \text{s}\) 4.22 23% \(\gamma \) 0.050 23%
4.27 77%
\({\text{}}^{237}\text{Np}\) \(2\text{.}\text{14}×{\text{10}}^{6}\text{y}\) \(\alpha \text{s}\) numerous \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) numerous <0.250%
4.96 (max.)
\({\text{}}^{239}\text{Pu}\) \(2\text{.}\text{41}×{\text{10}}^{4}\text{y}\) \(\alpha \text{s}\) 5.19 11% \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) \(7\text{.}5×{\text{10}}^{-5}\) 73%
5.23 15% 0.013 15%
5.24 73% 0.052 10%
others
\({\text{}}^{243}\text{Am}\) \(7\text{.}\text{37}×{\text{10}}^{3}\text{y}\) \(\alpha \text{s}\) Max. 5.44 \(\gamma \phantom{\rule{0.10em}{0ex}}\text{s}\) 0.075
5.37 88% others
5.32 11%
others

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Intro to Physics for Non-Majors Copyright © 2012 by OSCRiceUniversity is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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