Xenon-127

Properties and data of the isotope ¹²⁷Xe.

Contents

General Data

Radioactive Decay

Parent Nuclides

Use in Medicine

Isotones und Isobares

Literature

See also: List of individual Xenon isotopes (and general data sources).

General data

Name of the isotope:Xenon-127; Xe-127Symbol:¹²⁷Xe or 12754XeMass number A:127 (= number of nucleons)Atomic number Z:54 (= number of protons)Neutrons N:73Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.3518518518519 (= neutron-proton ratio)Neutron excess (N-Z):19Isotopic mass:126.905184(4) u (atomic weight of Xenon-127)Nuclide mass:126.8755626 u (calculated nuclear mass without electrons)Mass excess:-88.32054 MeVMass defect:1.149906596 u (per nucleus)Nuclear binding energy:1071.13109473 MeV (per nucleus)
8.43410311 MeV (average binding energy per nucleon)Separation energy:S_N = 7.246(5) MeV (first neutron)
S_P = 7.699(3) MeV (first proton)Half-life:36.346(3) dDecay constant λ:2.20726814836 × 10^-7 s^-1Specific activity α:1.05495870675 × 10⁺¹⁵ Bq g^-1
28512.397479811 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2+Magnetic dipole moment:μ(μ_N) = - 0.5033(11)Nuclear g-factor:g_l = -1.0066Charge radius:4.7747(38) femtometer fmYear of discovery:1950

Radioactive Decay

Half-life T_½ = 36.346(3) d respectively 3.1402944 × 10⁶ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC	¹²⁷I	100 %	0.662(5) MeV

Parent Nuclides

Direct parent isotope is: ¹²⁷Cs.

Xenon-127 as a Radionuclide in Medicine

The chemically inert noble gas isotope xenon-127 is one of the radiopharmaceuticals approved for medical applications and can be used as a radiodiagnostic for the respiratory tract (ATC code V09EX02).

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^127mXe	297.10(8) keV	69.2(9) s	9/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 73) and isobaric (same nucleon number A = 127) with Xenon-127. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 73	Isobar A = 127
41	¹¹⁴Nb
42	¹¹⁵Mo
43	¹¹⁶Tc
44	¹¹⁷Ru
45	¹¹⁸Rh	¹²⁷Rh
46	¹¹⁹Pd	¹²⁷Pd
47	¹²⁰Ag	¹²⁷Ag
48	¹²¹Cd	¹²⁷Cd
49	¹²²In	¹²⁷In
50	¹²³Sn	¹²⁷Sn
51	¹²⁴Sb	¹²⁷Sb
52	¹²⁵Te	¹²⁷Te
53	¹²⁶I	¹²⁷I
54	¹²⁷Xe	¹²⁷Xe
55	¹²⁸Cs	¹²⁷Cs
56	¹²⁹Ba	¹²⁷Ba
57	¹³⁰La	¹²⁷La
58	¹³¹Ce	¹²⁷Ce
59	¹³²Pr	¹²⁷Pr
60	¹³³Nd	¹²⁷Nd
61	¹³⁴Pm	¹²⁷Pm
62	¹³⁵Sm
63	¹³⁶Eu
64	¹³⁷Gd
65	¹³⁸Tb
66	¹³⁹Dy
67	¹⁴⁰Ho

External data and identifiers

Adopted Levels, Gammas:NuDat 127Xe

Literature and References

[1] - M. Rodrigues et al.:
Standardization of xenon-127 and measurement of photon emission intensities.
In: Applied Radiation and Isotopes, 87, 342-347, (2014), DOI 10.1016/j.apradiso.2013.11.066.