Xenon-125m2

Properties and data of the isotope ^125m2Xe.

Contents

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

General data

Name of the isotope:Xenon-125m2; Xe-125m2Symbol:^125m2Xe or 125m254XeMass number A:125 (= number of nucleons)Atomic number Z:54 (= number of protons)Neutrons N:71Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.3148148148148 (= neutron-proton ratio)Neutron excess (N-Z):17Excitation energy:295.89(15) keVIsotopic mass:124.906394(2) u (atomic weight of Xenon-125m2)Nuclide mass:124.8767726 u (calculated nuclear mass without electrons)Mass excess:-87.19343 MeVMass defect:1.131366764 u (per nucleus)Nuclear binding energy:1053.86135247 MeV (per nucleus)
8.43089082 MeV (average binding energy per nucleon)Half-life:0.14(3) μsDecay constant λ:4951051.2897139 s^-1Specific activity α:2.4045103444 × 10⁺²⁸ Bq g^-1
6.498676606675 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)7/2(+)Magnetic dipole moment:μ(μ_N) = +0.92(4)Quadrupole moment Q:1.40(15) barn (100 fm²)Nuclear g-factor:g_l = 0.26285714285714

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
¹²⁵Xe		16.9(2) h	1/2(+)
^125m1Xe	252.61(14) keV	57(1) s	9/2(-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 71) and isobaric (same nucleon number A = 125) with Xenon-125m2. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 71	Isobar A = 125
40	¹¹¹Zr
41	¹¹²Nb
42	¹¹³Mo
43	¹¹⁴Tc
44	¹¹⁵Ru
45	¹¹⁶Rh	¹²⁵Rh
46	¹¹⁷Pd	¹²⁵Pd
47	¹¹⁸Ag	¹²⁵Ag
48	¹¹⁹Cd	¹²⁵Cd
49	¹²⁰In	¹²⁵In
50	¹²¹Sn	¹²⁵Sn
51	¹²²Sb	¹²⁵Sb
52	¹²³Te	¹²⁵Te
53	¹²⁴I	¹²⁵I
54	¹²⁵Xe	¹²⁵Xe
55	¹²⁶Cs	¹²⁵Cs
56	¹²⁷Ba	¹²⁵Ba
57	¹²⁸La	¹²⁵La
58	¹²⁹Ce	¹²⁵Ce
59	¹³⁰Pr	¹²⁵Pr
60	¹³¹Nd	¹²⁵Nd
61	¹³²Pm
62	¹³³Sm
63	¹³⁴Eu
64	¹³⁵Gd
65	¹³⁶Tb