Tellurium-127

Properties and data of the isotope ¹²⁷Te.

Content

General data

Name of the isotope:Tellurium-127; Te-127Symbol:¹²⁷Te or 12752TeMass number A:127 (= number of nucleons)Atomic number Z:52 (= number of protons)Neutrons N:75Isotopic mass:126.9052257(16) u (atomic weight of Tellurium-127)Nuclide mass:126.8767013 u (calculated nuclear mass without electrons)Mass excess:-88.28169 MeVMass defect:1.151544664 u (per nucleus)Nuclear binding energy:1072.65694525 MeV (per nucleus)
8.44611768 MeV (average binding energy per nucleon)Separation energy:S_N = 6.28765(18) MeV (first neutron)
S_P = 9.18(3) MeV (first proton)Half-life:9.35(7) hDecay constant λ:2.059260785977 × 10^-5 s^-1Specific activity α:9.842189301983 × 10⁺¹⁶ Bq g^-1
2660051.1626982 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2+Magnetic dipole moment:μ(μ_N) = 0.635(4)Nuclear g-factor:g_l = 0.42333333333333Year of discovery:1938

Radioactive Decay

Half-life T_½ = 9.35(7) h (hours) respectively 3.3660 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹²⁷I	100 %	0.702(4) MeV

Parent Nuclides

Direct parent isotope is: ¹²⁷Sb.

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
^127mTe	88.23(7) keV	106.1(7) d	11/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 75) and isobaric (same nucleon number A = 127) with Tellurium-127. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 75	Isobar A = 127
42	¹¹⁷Mo
43	¹¹⁸Tc
44	¹¹⁹Ru
45	¹²⁰Rh	¹²⁷Rh
46	¹²¹Pd	¹²⁷Pd
47	¹²²Ag	¹²⁷Ag
48	¹²³Cd	¹²⁷Cd
49	¹²⁴In	¹²⁷In
50	¹²⁵Sn	¹²⁷Sn
51	¹²⁶Sb	¹²⁷Sb
52	¹²⁷Te	¹²⁷Te
53	¹²⁸I	¹²⁷I
54	¹²⁹Xe	¹²⁷Xe
55	¹³⁰Cs	¹²⁷Cs
56	¹³¹Ba	¹²⁷Ba
57	¹³²La	¹²⁷La
58	¹³³Ce	¹²⁷Ce
59	¹³⁴Pr	¹²⁷Pr
60	¹³⁵Nd	¹²⁷Nd
61	¹³⁶Pm	¹²⁷Pm
62	¹³⁷Sm
63	¹³⁸Eu
64	¹³⁹Gd
65	¹⁴⁰Tb
66	¹⁴¹Dy
67	¹⁴²Ho
68	¹⁴³Er
69	¹⁴⁴Tm