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Isotopes of radium

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Ra-226 nitrate (3x 1 mCi) - Photo by Dr Andrew R. Burgoyne - Oak Ridge National Laboratory

Ra-224 nitrate (21.4 mCi) - Photo by Dr Andrew R. Burgoyne - Oak Ridge National Laboratory

Isotopes ofradium (₈₈Ra)

Main isotopes^[1]			Decay
	abundance	half-life(t_1/2)	mode	product
²²³Ra	trace	11.43 d	α	²¹⁹Rn
²²⁴Ra	trace	3.6319 d	α	²²⁰Rn
²²⁵Ra	trace	14.9 d	β⁻	²²⁵Ac
²²⁵Ra	trace	14.9 d	α^[2]	²²¹Rn
²²⁶Ra	trace	1599 y	α	²²²Rn
²²⁸Ra	trace	5.75 y	β⁻	²²⁸Ac

Radium (₈₈Ra) has no stable or nearly stableisotopes, and thus astandard atomic weight cannot be given. The longest lived, and most common, isotope of radium is²²⁶Ra with a half-life of1600 years.²²⁶Ra occurs in thedecay chain of²³⁸U (often referred to as the radium series). Radium has 34 known isotopes from²⁰¹Ra to²³⁴Ra.

In the early history of the study of radioactivity, the different naturalisotopes of radium were given different names, as it was not untilFrederick Soddy's scientific career in the early 1900s that the concept of isotopes was realized.^[3] In this scheme,²²³Ra was named actinium X (AcX),²²⁴Ra thorium X (ThX),²²⁶Ra radium (Ra), and²²⁸Ra mesothorium 1 (MsTh₁).^[4] When it was realized that all of these are isotopes of the same element, many of these names fell out of use, and "radium" came to refer to all isotopes, not just²²⁶Ra,^[5] though mesothorium 1 in particular was still used for some time, with a footnote explaining that it referred to²²⁸Ra.^[6] Some of radium-226's decay products received historical names including "radium",^[7] ranging from radium A to radium G, with the letter indicating approximately how far they were down the chain from their parent²²⁶Ra.^[a]

In 2013 it was discovered that the nucleus of radium-224 is pear-shaped.^[10] This was the first discovery of an asymmetrical nucleus.

List of isotopes

[edit]

Nuclide ^{[n 1]}	Historic name	Z	N	Isotopic mass(Da)^[11] ^{[n 2]}^{[n 3]}	Half-life^[1]	Decay mode^[1] ^{[n 4]}	Daughter isotope ^{[n 5]}	Spin and parity^[1] ^{[n 6]}^{[n 7]}	Isotopic abundance
Nuclide ^{[n 1]}	Historic name	Excitation energy^{[n 7]}			Half-life^[1]	Decay mode^[1] ^{[n 4]}	Daughter isotope ^{[n 5]}	Spin and parity^[1] ^{[n 6]}^{[n 7]}	Isotopic abundance
²⁰¹Ra		88	113	201.012815(22)	20(30) ms	α	¹⁹⁷Rn	(3/2−)
^201mRa		263(26) keV			6(5) ms	α	¹⁹⁷Rn	13/2+
²⁰²Ra		88	114	202.009742(16)	4.1(11) ms	α	¹⁹⁸Rn	0+
²⁰³Ra		88	115	203.009234(10)	36(13) ms	α	¹⁹⁹Rn	3/2−
^203mRa		246(14) keV			25(5) ms	α	¹⁹⁹Rn	13/2+
²⁰⁴Ra		88	116	204.0065069(96)	60(9) ms	α (99.7%)	²⁰⁰Rn	0+
²⁰⁵Ra		88	117	205.006231(24)	220(50) ms	α	²⁰¹Rn	3/2−
^205mRa		263(25) keV			180(50) ms	α	²⁰¹Rn	13/2+
²⁰⁶Ra		88	118	206.003828(19)	0.24(2) s	α	²⁰²Rn	0+
²⁰⁷Ra		88	119	207.003772(63)	1.38(18) s	α (86%)	²⁰³Rn	5/2−#
²⁰⁷Ra		88	119	207.003772(63)	1.38(18) s	β⁺ (14%)	²⁰⁷Fr	5/2−#
^207mRa		560(60) keV			57(8) ms	IT (85#%)	²⁰⁷Ra	13/2+
^207mRa		560(60) keV			57(8) ms	α (?%)	²⁰³Rn	13/2+
²⁰⁸Ra		88	120	208.0018550(97)	1.110(45) s	α (87%)	²⁰⁴Rn	0+
²⁰⁸Ra		88	120	208.0018550(97)	1.110(45) s	β⁺ (13%)	²⁰⁸Fr	0+
^208mRa		2147.4(4) keV			263(17) ns	IT	²⁰⁸Ra	(8+)
²⁰⁹Ra		88	121	209.0019949(62)	4.71(8) s	α (90%)	²⁰⁵Rn	5/2−
^209mRa		882.4(7) keV			117(5) μs	α (90%)	²⁰⁵Rn	13/2+
^209mRa		882.4(7) keV			117(5) μs	β⁺ (10%)	²⁰⁹Fr	13/2+
²¹⁰Ra		88	122	210.0004754(99)	4.0(1) s	α	²⁰⁶Rn	0+
^210mRa		2050.9(7) keV			2.29(3) μs	IT	²¹⁰Ra	8+
²¹¹Ra		88	123	211.0008930(53)	12.6(12) s	α	²⁰⁷Rn	5/2−
^211mRa		1198.1(8) keV			9.5(3) μs	IT	²¹¹Ra	13/2+
²¹²Ra		88	124	211.999787(11)	13.0(2) s	α (?%)	²⁰⁸Rn	0+
²¹²Ra		88	124	211.999787(11)	13.0(2) s	β⁺ (?%)	²¹²Fr	0+
^212m1Ra		1958.4(20) keV			9.3(9) μs	IT	²¹²Ra	8+
^212m2Ra		2613.3(20) keV			0.85(13) μs	IT	²¹²Ra	11−
²¹³Ra		88	125	213.000371(11)	2.73(5) min	α (87%)	²⁰⁹Rn	1/2−
²¹³Ra		88	125	213.000371(11)	2.73(5) min	β⁺ (13%)	²¹³Fr	1/2−
^213mRa		1768(4) keV			2.20(5) ms	IT (99.4%)	²¹³Ra	(17/2−)
^213mRa		1768(4) keV			2.20(5) ms	α (0.6%)	²⁰⁹Rn	(17/2−)
²¹⁴Ra		88	126	214.0000996(56)	2.437(16) s	α (99.94%)	²¹⁰Rn	0+
²¹⁴Ra		88	126	214.0000996(56)	2.437(16) s	β⁺ (0.059%)	²¹⁴Fr	0+
^214m1Ra		1819.7(18) keV			118(7) ns	IT	²¹⁴Ra	6+
^214m2Ra		1865.2(18) keV			67.3(15) μs	IT (99.91%)	²¹⁴Ra	8+
^214m2Ra		1865.2(18) keV			67.3(15) μs	α (0.09%)	²¹⁰Rn	8+
^214m3Ra		2683.2(18) keV			295(7) ns	IT	²¹⁴Ra	11−
^214m4Ra		3478.4(18) keV			279(4) ns	IT	²¹⁴Ra	14+
^214m5Ra		4146.8(18) keV			225(4) ns	IT	²¹⁴Ra	17−
^214m6Ra		6577.0(18) keV			128(4) ns	IT	²¹⁴Ra	(25−)
²¹⁵Ra		88	127	215.0027182(77)	1.669(9) ms	α	²¹¹Rn	9/2+#
^215m1Ra		1877.8(3) keV			7.31(13) μs	IT	²¹⁵Ra	(25/2+)
^215m2Ra		2246.9(4) keV			1.39(7) μs	IT	²¹⁵Ra	(29/2−)
^215m3Ra		3807(50)# keV			555(10) ns	IT	²¹⁵Ra	(43/2−)
²¹⁶Ra		88	128	216.0035335(86)	172(7) ns	α	²¹²Rn	0+
²¹⁶Ra		88	128	216.0035335(86)	172(7) ns	EC (<1×10⁻⁸%)	²¹⁶Fr	0+
²¹⁷Ra		88	129	217.0063227(76)	1.95(12) μs	α	²¹³Rn	(9/2+)
²¹⁸Ra		88	130	218.007134(11)	25.91(14) μs	α	²¹⁴Rn	0+
²¹⁹Ra		88	131	219.0100847(73)	9(2) ms	α	²¹⁵Rn	(7/2)+
^219mRa		16.7(8) keV			10(3) ns	α	²¹⁵Rn	(11/2)+
²²⁰Ra		88	132	220.0110275(82)	18.1(12) ms	α	²¹⁶Rn	0+
²²¹Ra		88	133	221.0139173(05)	25(4) s	α	²¹⁷Rn	5/2+	Trace^{[n 8]}
²²¹Ra		88	133	221.0139173(05)	25(4) s	CD (1.2×10⁻¹⁰%)^{[n 9]}	²⁰⁷Pb ¹⁴C	5/2+	Trace^{[n 8]}
²²²Ra		88	134	222.0153734(48)	33.6(4) s	α	²¹⁸Rn	0+
²²²Ra		88	134	222.0153734(48)	33.6(4) s	CD (3.0×10⁻⁸%)	²⁰⁸Pb ¹⁴C	0+
²²³Ra^{[n 10]}	Actinium X	88	135	223.0185006(22)	11.4352(10) d	α	²¹⁹Rn	3/2+	Trace^{[n 11]}
²²³Ra^{[n 10]}	Actinium X	88	135	223.0185006(22)	11.4352(10) d	CD (8.9×10⁻⁸%)	²⁰⁹Pb ¹⁴C	3/2+	Trace^{[n 11]}
²²⁴Ra	Thorium X	88	136	224.0202104(19)	3.6316(14) d	α	²²⁰Rn	0+	Trace^{[n 12]}
²²⁴Ra	Thorium X	88	136	224.0202104(19)	3.6316(14) d	CD (4.0×10⁻⁹%)	²¹⁰Pb ¹⁴C	0+	Trace^{[n 12]}
²²⁵Ra		88	137	225.0236105(28)	14.82(19) d	β⁻	²²⁵Ac	1/2+	Trace^{[n 13]}
²²⁵Ra		88	137	225.0236105(28)	14.82(19) d	α (2.6×10⁻³%)^[2]	²²¹Rn	1/2+	Trace^{[n 13]}
²²⁶Ra	Radium^{[n 14]}	88	138	226.0254082(21)	1600(7) y	α^{[n 15]}	²²²Rn	0+	Trace^{[n 16]}
²²⁶Ra	Radium^{[n 14]}	88	138	226.0254082(21)	1600(7) y	CD (2.6×10⁻⁹%)	²¹²Pb ¹⁴C	0+	Trace^{[n 16]}
²²⁷Ra		88	139	227.0291762(21)	42.2(5) min	β⁻	²²⁷Ac	3/2+
²²⁸Ra	Mesothorium 1	88	140	228.0310686(21)	5.75(3) y	β⁻	²²⁸Ac	0+	Trace^{[n 12]}
²²⁹Ra		88	141	229.034957(17)	4.0(2) min	β⁻	²²⁹Ac	5/2+
²³⁰Ra		88	142	230.037055(11)	93(2) min	β⁻	²³⁰Ac	0+
²³¹Ra		88	143	231.041027(12)	104(1) s	β⁻	²³¹Ac	(5/2+)
^231mRa		66.21(9) keV			~53 μs	IT	²³¹Ra	(1/2+)
²³²Ra		88	144	232.0434753(98)	4.0(3) min	β⁻	²³²Ac	0+
²³³Ra		88	145	233.0475946(92)	30(5) s	β⁻	²³³Ac	1/2+#
²³⁴Ra		88	146	234.0503821(90)	30(10) s	β⁻	²³⁴Ac	0+
This table header & footer: view

^^mRa – Excitednuclear isomer.
^( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
^# – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
^Modes of decay:
EC: Electron capture
CD: Cluster decay
IT: Isomeric transition
^Bold symbol as daughter – Daughter product is stable.
^( ) spin value – Indicates spin with weak assignment arguments.
^^a ^b# – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
^Intermediate decay product of²³⁷Np
^Lightest known nuclide to undergocluster decay
^Used fortreating bone cancer
^Intermediatedecay product of²³⁵U
^^a ^bIntermediate decay product of²³²Th
^Intermediate decay product of²³⁷Np
^Source of element's name
^Theoretically capable of β⁻β⁻ decay to²²⁶Th
^Intermediate decay product of²³⁸U

Actinides vs fission products

[edit]

Actinides and fission products by half-life v t e
Actinides^[12] bydecay chain				Half-life range (a)	Fission products of²³⁵U byyield^[13]
4n	4n + 1	4n + 2	4n + 3	Half-life range (a)	4.5–7%	0.04–1.25%	<0.001%
²²⁸Ra^№				4–6 a		¹⁵⁵Eu^þ
²⁴⁸Bk^[14]				> 9 a
²⁴⁴Cm^ƒ	²⁴¹Pu^ƒ	²⁵⁰Cf	²²⁷Ac^№	10–29 a	⁹⁰Sr	⁸⁵Kr	^113mCd^þ
²³²U^ƒ		²³⁸Pu^ƒ	²⁴³Cm^ƒ	29–97 a	¹³⁷Cs	¹⁵¹Sm^þ	^121mSn
	²⁴⁹Cf^ƒ	^242mAm^ƒ		141–351 a	No fission products have ahalf-life in the range of 100 a–210 ka ...
	²⁴¹Am^ƒ		²⁵¹Cf^ƒ^[15]	430–900 a
		²²⁶Ra^№	²⁴⁷Bk	1.3–1.6 ka
²⁴⁰Pu	²²⁹Th	²⁴⁶Cm^ƒ	²⁴³Am^ƒ	4.7–7.4 ka
	²⁴⁵Cm^ƒ	²⁵⁰Cm		8.3–8.5 ka
			²³⁹Pu^ƒ	24.1 ka
		²³⁰Th^№	²³¹Pa^№	32–76 ka
²³⁶Np^ƒ	²³³U^ƒ	²³⁴U^№		150–250 ka	⁹⁹Tc^₡	¹²⁶Sn
²⁴⁸Cm		²⁴²Pu		327–375 ka		⁷⁹Se^₡
				1.33 Ma	¹³⁵Cs^₡
	²³⁷Np^ƒ			1.61–6.5 Ma	⁹³Zr	¹⁰⁷Pd
²³⁶U			²⁴⁷Cm^ƒ	15–24 Ma		¹²⁹I^₡
²⁴⁴Pu				80 Ma	... nor beyond 15.7 Ma^[16]
²³²Th^№		²³⁸U^№	²³⁵U^ƒ№	0.7–14.1 Ga	... nor beyond 15.7 Ma^[16]
₡, has thermalneutron capture cross section in the range of 8–50 barns ƒ, fissile №, primarily anaturally occurring radioactive material (NORM) þ, neutron poison (thermal neutron capture cross section greater than 3k barns)

References

[edit]

^^a ^b ^c ^dKondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021)."The NUBASE2020 evaluation of nuclear properties"(PDF).Chinese Physics C.45 (3): 030001.doi:10.1088/1674-1137/abddae.
^^a ^bLiang, C. F.; Paris, P.; Sheline, R. K. (2000-09-19). "α decay of²²⁵Ra".Physical Review C.62 (4). American Physical Society (APS): 047303.Bibcode:2000PhRvC..62d7303L.doi:10.1103/physrevc.62.047303.ISSN 0556-2813.
^Nagel, Miriam C. (September 1982)."Frederick Soddy: From alchemy to isotopes".Journal of Chemical Education.59 (9): 739.Bibcode:1982JChEd..59..739N.doi:10.1021/ed059p739.ISSN 0021-9584.
^Kirby, H.W. & Salutsky, Murrell L. (December 1964).The Radiochemistry of Radium (Report). crediting UNT Libraries Government Documents Department. p. 3 – viaUniversity of North Texas, UNT Digital Library. Alternate source:https://sgp.fas.org/othergov/doe/lanl/lib-www/books/rc000041.pdf
^Giunta, Carmen J. (2017)."ISOTOPES: IDENTIFYING THE BREAKTHROUGH PUBLICATION (1)"(PDF).Bull. Hist. Chem.42 (2):103–111.
^Looney, William B. (1958)."Effects of Radium in Man".Science.127 (3299):630–633.Bibcode:1958Sci...127..630L.doi:10.1126/science.127.3299.630.ISSN 0036-8075.JSTOR 1755774.PMID 13529029.
^Mitchell, S. A."Is Radium in the Sun?".Popular Astronomy.21:321–331.Bibcode:1913PA.....21..321M.
^Kuhn, W. (1929). "LXVIII. Scattering of thorium C" γ-radiation by radium G and ordinary lead".The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science.8 (52): 628.doi:10.1080/14786441108564923.ISSN 1941-5982.
^Kinsey, R. R. (December 18, 1997),"The radioactive series of radium-226"(PDF),The NUDAT/PCNUDAT Program for Nuclear Data – via CERN
^Hills, Stephanie (8 May 2013)."First observations of short-lived pear-shaped atomic nuclei".CERN.
^Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*".Chinese Physics C.45 (3): 030003.doi:10.1088/1674-1137/abddaf.
^Plus radium (element 88). While actually a sub-actinide, it immediately precedes actinium (89) and follows a three-element gap of instability afterpolonium (84) where no nuclides have half-lives of at least four years (the longest-lived nuclide in the gap isradon-222 with a half life of less than fourdays). Radium's longest lived isotope, at 1,600 years, thus merits the element's inclusion here.
^Specifically fromthermal neutron fission of uranium-235, e.g. in a typicalnuclear reactor.
^Milsted, J.; Friedman, A. M.; Stevens, C. M. (1965). "The alpha half-life of berkelium-247; a new long-lived isomer of berkelium-248".Nuclear Physics.71 (2): 299.Bibcode:1965NucPh..71..299M.doi:10.1016/0029-5582(65)90719-4.
"The isotopic analyses disclosed a species of mass 248 in constant abundance in three samples analysed over a period of about 10 months. This was ascribed to an isomer of Bk²⁴⁸ with a half-life greater than 9 [years]. No growth of Cf²⁴⁸ was detected, and a lower limit for the β⁻ half-life can be set at about 10⁴ [years]. No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]."
^This is the heaviest nuclide with a half-life of at least four years before the "sea of instability".
^Excluding those "classically stable" nuclides with half-lives significantly in excess of²³²Th; e.g., while^113mCd has a half-life of only fourteen years, that of¹¹³Cd is eightquadrillion years.

Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean;Wapstra, Aaldert Hendrik (2003),"The NUBASE evaluation of nuclear and decay properties",Nuclear Physics A,729:3–128,Bibcode:2003NuPhA.729....3A,doi:10.1016/j.nuclphysa.2003.11.001
Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean;Wapstra, Aaldert Hendrik (2003),"The NUBASE evaluation of nuclear and decay properties",Nuclear Physics A,729:3–128,Bibcode:2003NuPhA.729....3A,doi:10.1016/j.nuclphysa.2003.11.001
- National Nuclear Data Center."NuDat 2.x database".Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.).CRC Handbook of Chemistry and Physics (85th ed.).Boca Raton, Florida:CRC Press.ISBN 978-0-8493-0485-9.

Notes

[edit]

^Radium emanation =²²²Rn,Ra A =²¹⁸Po,Ra B =²¹⁴Pb,Ra C =²¹⁴Bi,Ra C₁ =²¹⁴Po,Ra C₂ =²¹⁰Tl,Ra D =²¹⁰Pb,Ra E =²¹⁰Bi,Ra F =²¹⁰Po, andRa G =²⁰⁶Pb.^[8]^[9]

Isotopes of thechemical elements

Group	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
Period	Hydrogen and alkali metals	Alkaline earth metals													Pnictogens	Chalcogens	Halogens	Noble gases
①	Isotopes § List H 1																	Isotopes § List He 2
②	Isotopes § List Li 3	Isotopes § List Be 4											Isotopes § List B 5	Isotopes § List C 6	Isotopes § List N 7	Isotopes § List O 8	Isotopes § List F 9	Isotopes § List Ne 10
③	Isotopes § List Na 11	Isotopes § List Mg 12											Isotopes § List Al 13	Isotopes § List Si 14	Isotopes § List P 15	Isotopes § List S 16	Isotopes § List Cl 17	Isotopes § List Ar 18
④	Isotopes § List K 19	Isotopes § List Ca 20	Isotopes § List Sc 21	Isotopes § List Ti 22	Isotopes § List V 23	Isotopes § List Cr 24	Isotopes § List Mn 25	Isotopes § List Fe 26	Isotopes § List Co 27	Isotopes § List Ni 28	Isotopes § List Cu 29	Isotopes § List Zn 30	Isotopes § List Ga 31	Isotopes § List Ge 32	Isotopes § List As 33	Isotopes § List Se 34	Isotopes § List Br 35	Isotopes § List Kr 36
⑤	Isotopes § List Rb 37	Isotopes § List Sr 38	Isotopes § List Y 39	Isotopes § List Zr 40	Isotopes § List Nb 41	Isotopes § List Mo 42	Isotopes § List Tc 43	Isotopes § List Ru 44	Isotopes § List Rh 45	Isotopes § List Pd 46	Isotopes § List Ag 47	Isotopes § List Cd 48	Isotopes § List In 49	Isotopes § List Sn 50	Isotopes § List Sb 51	Isotopes § List Te 52	Isotopes § List I 53	Isotopes § List Xe 54
⑥	Isotopes § List Cs 55	Isotopes § List Ba 56	Isotopes § List Lu 71	Isotopes § List Hf 72	Isotopes § List Ta 73	Isotopes § List W 74	Isotopes § List Re 75	Isotopes § List Os 76	Isotopes § List Ir 77	Isotopes § List Pt 78	Isotopes § List Au 79	Isotopes § List Hg 80	Isotopes § List Tl 81	Isotopes § List Pb 82	Isotopes § List Bi 83	Isotopes § List Po 84	Isotopes § List At 85	Isotopes § List Rn 86
⑦	Isotopes § List Fr 87	Isotopes § List Ra 88	Isotopes § List Lr 103	Isotopes § List Rf 104	Isotopes § List Db 105	Isotopes § List Sg 106	Isotopes § List Bh 107	Isotopes § List Hs 108	Isotopes § List Mt 109	Isotopes § List Ds 110	Isotopes § List Rg 111	Isotopes § List Cn 112	Isotopes § List Nh 113	Isotopes § List Fl 114	Isotopes § List Mc 115	Isotopes § List Lv 116	Isotopes § List Ts 117	Isotopes § List Og 118
⑧	Isotopes § List Uue 119	Isotopes § List Ubn 120

			Isotopes § List La 57	Isotopes § List Ce 58	Isotopes § List Pr 59	Isotopes § List Nd 60	Isotopes § List Pm 61	Isotopes § List Sm 62	Isotopes § List Eu 63	Isotopes § List Gd 64	Isotopes § List Tb 65	Isotopes § List Dy 66	Isotopes § List Ho 67	Isotopes § List Er 68	Isotopes § List Tm 69	Isotopes § List Yb 70
			Isotopes § List Ac 89	Isotopes § List Th 90	Isotopes § List Pa 91	Isotopes § List U 92	Isotopes § List Np 93	Isotopes § List Pu 94	Isotopes § List Am 95	Isotopes § List Cm 96	Isotopes § List Bk 97	Isotopes § List Cf 98	Isotopes § List Es 99	Isotopes § List Fm 100	Isotopes § List Md 101	Isotopes § List No 102

Authority control databases: National	United States Israel

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