Isotopes of germanium - AbsoluteAstronomy.com

Germanium
Germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon. The isolated element is a semiconductor, with an appearance most similar to elemental silicon....

(Ge) has five naturally occurring isotope

Isotope

Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...

s, ⁷⁰Ge, ⁷²Ge, ⁷³Ge, ⁷⁴Ge, and ⁷⁶Ge. Of these, ⁷⁶Ge is very slightly radioactive, decaying by double beta decay

Double beta decay

Double beta decay is a radioactive decay process where a nucleus releases two beta rays as a single process.In double-beta decay, two neutrons in the nucleus are converted to protons, and two electrons and two electron antineutrinos are emitted...

with a half-life

Half-life

Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...

of 1.78 × 10²¹ years (130 million million times the age of the universe), giving it the distinction of being the nuclide with the longest directly measured half-life (tellurium-128 has a half-life > 1000 times longer, but it has been indirectly measured by decay products in ancient rocks).

Stable ⁷⁴Ge is the most common isotope, having a natural abundance

Natural abundance

In chemistry, natural abundance refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass of these isotopes is the atomic weight listed for the element in the periodic table...

of approximately 36%. ⁷⁶Ge is the least common with a natural abundance of approximately 7%. When bombarded with alpha particles, the isotopes ⁷²Ge and ⁷⁶Ge will generate stable ⁷⁵As and ⁷⁷Se, releasing high energy electrons in the process.

At least 27 radioisotopes have also been synthesized ranging in atomic mass from 58 to 89. The most stable of these is ⁶⁸Ge, decaying by electron capture

Electron capture

Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...

with a half-life of 270.95 d. It decays to the medically useful positron-emitting isotope ⁶⁸Ga. (See gallium-68 generator

Gallium-68 generator

A gallium-68 generator is a device used to extract the positron-emitting isotope 68Ga of gallium from a source of decaying germanium-68. The parent isotope 68Ge has a half-life of 271 days and can be easily sent to hospitals within the generator, where it is storable for almost a year...

for notes on the source of this isotope, and its medical use). The least stable known germanium stable is ⁶⁰Ge with a half-life of 30 ms.

While most of germanium's radioisotopes decay by beta decay

Beta decay

In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...

, ⁶¹Ge and ⁶⁴Ge decay by β⁺

Positron emission

Positron emission or beta plus decay is a type of beta decay in which a proton is converted, via the weak force, to a neutron, releasing a positron and a neutrino....

delayed proton emission

Proton emission

Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very...

. ⁸⁴Ge through ⁸⁷Ge also have minor β^-

Beta decay

delayed neutron emission

Neutron emission

Neutron emission is a type of radioactive decay of atoms containing excess neutrons, in which a neutron is simply ejected from the nucleus. Two examples of isotopes which emit neutrons are helium-5 and beryllium-13...

decay paths.

Standard atomic mass: 72.64(1) u

Table

nuclide symbol	Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... )	N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... )	isotopic mass (u)	half-lifeBold for isotopes with half-lives longer than the age of the universe (nearly stable)	decay mode(s)Abbreviations: EC: Electron capture Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... IT: Isomeric transition Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer....	daughter isotope(s)Bold for stable isotopes	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy					daughter isotope(s)Bold for stable isotopes	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
⁵⁸Ge	32	26	57.99101(34)#		2p Proton decay In particle physics, proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron...	⁵⁶Zn	0+
⁵⁹Ge	32	27	58.98175(30)#		2p	⁵⁷Zn	7/2-#
⁶⁰Ge	32	28	59.97019(25)#	30# ms	β⁺ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...	⁶⁰Ga	0+
⁶⁰Ge	32	28	59.97019(25)#	30# ms	2p	⁵⁸Zn	0+
⁶¹Ge	32	29	60.96379(32)#	39(12) ms	β⁺, p (80%)	⁶⁰Zn	(3/2-)#
⁶¹Ge	32	29	60.96379(32)#	39(12) ms	β⁺ (20%)	⁶¹Ga	(3/2-)#
⁶²Ge	32	30	61.95465(15)#	129(35) ms	β⁺	⁶²Ga	0+
⁶³Ge	32	31	62.94964(21)#	142(8) ms	β⁺	⁶³Ga	(3/2-)#
⁶⁴Ge	32	32	63.94165(3)	63.7(25) s	β⁺	⁶⁴Ga	0+
⁶⁵Ge	32	33	64.93944(11)	30.9(5) s	β⁺ (99.99%)	⁶⁵Ga	(3/2)-
⁶⁵Ge	32	33	64.93944(11)	30.9(5) s	β⁺, p (.01%)	⁶⁴Zn	(3/2)-
⁶⁶Ge	32	34	65.93384(3)	2.26(5) h	β⁺	⁶⁶Ga	0+
⁶⁷Ge	32	35	66.932734(5)	18.9(3) min	β⁺	⁶⁷Ga	1/2-
^67m1Ge	18.20(5) keV			13.7(9) µs			5/2-
^67m2Ge	751.70(6) keV			110.9(14) ns			9/2+
⁶⁸GeUsed to generate Gallium-68 generator A gallium-68 generator is a device used to extract the positron-emitting isotope 68Ga of gallium from a source of decaying germanium-68. The parent isotope 68Ge has a half-life of 271 days and can be easily sent to hospitals within the generator, where it is storable for almost a year... ⁶⁸Ga	32	36	67.928094(7)	270.95(16) d	EC Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...	⁶⁸Ga	0+
⁶⁹Ge	32	37	68.9279645(14)	39.05(10) h	β⁺	⁶⁹Ga	5/2-
^69m1Ge	86.765(14) keV			5.1(2) µs			1/2-
^69m2Ge	397.944(18) keV			2.81(5) µs			9/2+
⁷⁰Ge	32	38	69.9242474(11)	Stable			0+	0.2038(18)
⁷¹Ge	32	39	70.9249510(11)	11.43(3) d	EC	⁷¹Ga	1/2-
^71mGe	198.367(10) keV			20.40(17) ms	IT Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer....	⁷¹Ge	9/2+
⁷²Ge	32	40	71.9220758(18)	Stable			0+	0.2731(26)
^72mGe	691.43(4) keV			444.2(8) ns			0+
⁷³Ge	32	41	72.9234589(18)	Stable			9/2+	0.0776(8)
^73m1Ge	13.2845(15) keV			2.92(3) µs			5/2+
^73m2Ge	66.726(9) keV			499(11) ms			1/2-
⁷⁴Ge	32	42	73.9211778(18)	Stable			0+	0.3672(15)
⁷⁵Ge	32	43	74.9228589(18)	82.78(4) min	β^-	⁷⁵As	1/2-
^75m1Ge	139.69(3) keV			47.7(5) s	IT (99.97%)	⁷⁵Ge	7/2+
^75m1Ge	139.69(3) keV			47.7(5) s	β^-	⁷⁵As	7/2+
^75m2Ge	192.18(7) keV			216(5) ns			5/2+
⁷⁶GePrimordial Primordial nuclide In geochemistry and geonuclear physics, primordial nuclides or primordial isotopes are nuclides found on the earth that have existed in their current form since before Earth was formed. Only 288 such nuclides are known... radionuclide Radionuclide A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma...	32	44	75.9214026(18)	1.78(8)×10²¹ aLongest directly measured half-life Half-life Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to... of all known radioisotopes	β^-β^-	⁷⁶Se	0+	0.0783(7)
⁷⁷Ge	32	45	76.9235486(18)	11.30(1) h	β^-	⁷⁷As	7/2+
^77mGe	159.70(10) keV			52.9(6) s	β^- (79%)	⁷⁷As	1/2-
^77mGe	159.70(10) keV			52.9(6) s	IT (21%)	⁷⁷Ge	1/2-
⁷⁸Ge	32	46	77.922853(4)	88(1) min	β^-	⁷⁸As	0+
⁷⁹Ge	32	47	78.9254(1)	18.98(3) s	β^-	⁷⁹As	(1/2)-
^79mGe	185.95(4) keV			39.0(10) s	β^- (96%)	⁷⁹As	(7/2+)#
^79mGe	185.95(4) keV			39.0(10) s	IT (4%)	⁷⁹Ge	(7/2+)#
⁸⁰Ge	32	48	79.92537(3)	29.5(4) s	β^-	⁸⁰As	0+
⁸¹Ge	32	49	80.92882(13)	7.6(6) s	β^-	⁸¹As	9/2+#
^81mGe	679.13(4) keV			7.6(6) s	β^- (99%)	⁸¹As	(1/2+)
^81mGe	679.13(4) keV			7.6(6) s	IT (1%)	⁸¹Ge	(1/2+)
⁸²Ge	32	50	81.92955(26)	4.55(5) s	β^-	⁸²As	0+
⁸³Ge	32	51	82.93462(21)#	1.85(6) s	β^-	⁸³As	(5/2+)#
⁸⁴Ge	32	52	83.93747(32)#	0.947(11) s	β^- (89.2%)	⁸⁴As	0+
⁸⁴Ge	32	52	83.93747(32)#	0.947(11) s	β^-, n (10.8%)	⁸³As	0+
⁸⁵Ge	32	53	84.94303(43)#	535(47) ms	β^- (86%)	⁸⁵As	5/2+#
⁸⁵Ge	32	53	84.94303(43)#	535(47) ms	β^-, n (14%)	⁸⁴As	5/2+#
⁸⁶Ge	32	54	85.94649(54)#	>150 ns	β^-, n	⁸⁵As	0+
⁸⁶Ge	32	54	85.94649(54)#	>150 ns	β^-	⁸⁶As	0+
⁸⁷Ge	32	55	86.95251(54)#	0.14# s			5/2+#
⁸⁸Ge	32	56	87.95691(75)#	>=300 ns			0+
⁸⁹Ge	32	57	88.96383(97)#	>150 ns			3/2+#

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