Selected Radioactive Isotopes

This table lists selected emissions. Decay modes are alpha decay (α), beta-minus decay (

β^{-}

), positron emission (

β^{+}

), electron capture (EC), and isomeric transition (IT). The suffix m identifies a metastable nuclear state. Alpha energies are the kinetic energies of the emitted particles, excluding daughter-nucleus recoil. Beta energies are spectrum endpoints; the mean energy depends on the spectrum and is not generally half the endpoint. EC and IT have no particle energy listed in that column.

Particle yields are emitted particles per 100 decays of the listed isotope; entries beside EC or IT give decays through that mode per 100 decays. Photon yields are gamma photons per 100 parent decays, including the indicated daughter de-excitations, rather than probabilities for transitions that can also produce conversion electrons. Daughter isomers can delay photon emission. The left and right entries on the same line are independent lists, not necessarily coincident emissions. Only selected emissions are shown; yields need not sum to 100. X-rays, conversion electrons, annihilation photons, and later radioactive-daughter emissions are omitted, except for the listed Ba-137m and Mn-52m transitions following Cs-137 and Fe-52 decay.

Table B.1. Selected Radioactive Isotopes
Isotope	$t_{1 / 2}$	Decay mode	Particle energy (MeV)	Per 100 decays	Photon	Photon energy (MeV)	Photons per 100 decays
${}^{3}H$	12.32(2) y	$β^{-}$	0.0186	100
${}^{14}C$	$5.70(3) \times 10^{3} y$	$β^{-}$	0.1565	100
${}^{13}N$	9.965(4) min	$β^{+}$	1.198	99.8
		EC		0.197
${}^{22}{Na}$	2.6019(6) y	$β^{+}$	0.5464	90.3	$γ$	1.275	99.9
		EC		9.64
${}^{32}P$	14.269(7) d	$β^{-}$	1.711	100
${}^{35}S$	87.37(4) d	$β^{-}$	0.1673	100
${}^{36}{Cl}$	$3.013(15) \times 10^{5} y$	$β^{-}$	0.7095	98.1
		EC		1.9
${}^{40}K$	$1.248(3) \times 10^{9} y$	$β^{-}$	1.311	89.6	$γ$	1.461	10.3
		EC		10.4
${}^{43}K$	22.3(1) h	$β^{-}$	0.827	92.2	$γ$	0.3728	87.3
					$γ$	0.6175	80.5
${}^{45}{Ca}$	162.61(9) d	$β^{-}$	0.2580	≈100
${}^{51}{Cr}$	27.7015(11) d	EC		100	$γ$	0.3201	9.89
${}^{52}{Mn}$	5.591(3) d	$β^{+}$	0.576	30.9	$γ$	1.334	5.08
		EC		≈69	$γ$	1.434	≈100
${}^{52}{Fe}$	8.275(8) h	$β^{+}$	0.807	56.1	$γ$	0.1687	99.1
		EC		43.9	$γ$	0.3777	1.64
${}^{59}{Fe}$	44.500(12) d	$β^{-}$	0.2734	45.2	$γ$	1.099	56.5
		$β^{-}$	0.4657	53.3	$γ$	1.292	43.2
${}^{60}{Co}$	5.2714(6) y	$β^{-}$	0.3173	99.9	$γ$	1.173	99.9
					$γ$	1.332	≈100
${}^{65}{Zn}$	243.94(4) d	EC		98.6	$γ$	1.116	50.2
		$β^{+}$	0.3299	1.42
${}^{67}{Ga}$	3.2617(4) d	EC		100	$γ$	0.09331	38.1
					$γ$	0.1846	21.0
					$γ$	0.3002	16.6
${}^{75}{Se}$	119.78(3) d	EC		100	$γ$	0.1211	16.9
					$γ$	0.1360	57.7
					$γ$	0.2647	58.8
					$γ$	0.2795	24.9
${}^{86}{Rb}$	18.645(8) d	$β^{-}$	0.698	8.71	$γ$	1.077	8.71
		$β^{-}$	1.774	91.3
${}^{85}{Sr}$	64.846(6) d	EC		100	$γ$	0.5140	98.5
${}^{90}{Sr}$	28.91(3) y	$β^{-}$	0.546	100
${}^{90}Y$	64.05(5) h	$β^{-}$	2.279	≈100
${}^{99m}{Tc}$	6.0066(2) h	IT		≈100	$γ$	0.1405	88.5
${}^{113m}{In}$	1.6579(4) h	IT		100	$γ$	0.3917	65.0
${}^{123}I$	13.2232(15) h	EC		100	$γ$	0.1590	83.3
${}^{131}I$	8.0249(6) d	$β^{-}$	0.2479	2.13	$γ$	0.3645	81.2
		$β^{-}$	0.6063	89.4
${}^{129}{Cs}$	32.06(6) h	EC			$γ$	0.03958	2.97
					$γ$	0.3719	30.6
					$γ$	0.4115	22.3
${}^{137}{Cs}$	30.04(4) y	$β^{-}$	0.5140	94.6	$γ$	0.6617	85.0
		$β^{-}$	1.176	5.43
${}^{140}{Ba}$	12.7534(21) d	$β^{-}$	0.467	24.9	$γ$	0.02996	14.4
		$β^{-}$	1.004	35.6	$γ$	0.1627	6.49
		$β^{-}$	1.018	25.6	$γ$	0.5373	24.6
${}^{198}{Au}$	2.69464(14) d	$β^{-}$	0.9610	99.0	$γ$	0.4118	95.6
${}^{197}{Hg}$	64.93(7) h	EC		100	$γ$	0.07735	18.8
${}^{210}{Po}$	138.376(2) d	$α$	5.304	≈100
${}^{226}{Ra}$	$1.600(7) \times 10^{3} y$	$α$	4.601	5.95	$γ$	0.1862	3.56
		$α$	4.784	94.0
${}^{235}U$	$7.04(1) \times 10^{8} y$	$α$	4.215	5.95	$γ$	0.1438	10.9
		$α$	4.366	18.8	$γ$	0.1634	5.08
		$α$	4.398	57.2	$γ$	0.1857	57.0
${}^{238}U$	$4.463(3) \times 10^{9} y$	$α$	4.151	22.3	$γ$	0.04955	0.0697
		$α$	4.198	77.5
${}^{237}{Np}$	$2.144(7) \times 10^{6} y$	$α$	4.767	9.5	$γ$	0.02937	14.3
		$α$	4.771	23.0	$γ$	0.08648	12.3
		$α$	4.788	47.6
${}^{239}{Pu}$	$2.411(3) \times 10^{4} y$	$α$	5.106	11.9	$γ$	$7.65 \times 10^{−5}$	$\approx 10^{−8}$
		$α$	5.144	17.1	$γ$	0.01298	0.0341
		$α$	5.157	70.8	$γ$	0.05162	0.0269
${}^{243}{Am}$	$7.350(9) \times 10^{3} y$	$α$	5.233	11.5	$γ$	0.07466	67.2
		$α$	5.275	86.7
		$α$	5.349	0.240

Half-lives follow NUBASE2020, consistent with Appendix A. Parentheses give uncertainty in the last quoted digits. Emission data are rounded selections from the sources below; they may use a different evaluation of branching fractions from NUBASE2020.

Radiation energies and yields follow the DDEP evaluated tables, except for potassium-43, rubidium-86, indium-113m, and mercury-197 (LNHB Nucléide-Lara) and cesium-129 (ICRP Publication 107 data reproduced by MIRDspecs). Potassium-43 and rubidium-86 beta endpoints are calculated from the LNHB decay-scheme energy differences. Sodium-22 and potassium-40 branching fractions follow DDEP consistently with their emission data. The sources provide full decay schemes, evaluation dates, and uncertainties. These selected, rounded data are intended for teaching.