Thallium-216

Properties and data of the isotope ²¹⁶Tl.

Content

General data

Name of the isotope:Thallium-216; Tl-216Symbol:²¹⁶Tl or 21681TlMass number A:216 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:135Isotopic mass:216.01580(32) u (atomic weight of Thallium-216)Nuclide mass:215.97137 u (calculated nuclear mass without electrons)Mass excess:14.71761 MeVMass defect:1.787791252 u (per nucleus)Nuclear binding energy:1665.31682449 MeV (per nucleus)
7.70980011 MeV (average binding energy per nucleon)Separation energy:S_N = 3.26(42) MeV (first neutron)
S_P = 8.78(50) MeV (first proton)Half-life:> 300 nsDecay constant λ:2310490.6018665 s^-1Specific activity α:6.441712898148 × 10⁺²⁷ Bq g^-1
1.74100348598 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2010

Radioactive Decay

Half-life T_½ = > 300 ns respectively 3.0 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²¹⁶Pb	?	7.24(36) MeV
β^-, n	²¹⁵Pb	?	2.3(3) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 135) and isobaric (same nucleon number A = 216) with Thallium-216. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 135	Isobar A = 216
80	²¹⁵Hg	²¹⁶Hg
81	²¹⁶Tl	²¹⁶Tl
82	²¹⁷Pb	²¹⁶Pb
83	²¹⁸Bi	²¹⁶Bi
84	²¹⁹Po	²¹⁶Po
85	²²⁰At	²¹⁶At
86	²²¹Rn	²¹⁶Rn
87	²²²Fr	²¹⁶Fr
88	²²³Ra	²¹⁶Ra
89	²²⁴Ac	²¹⁶Ac
90	²²⁵Th	²¹⁶Th
91	²²⁶Pa	²¹⁶Pa
92	²²⁷U	²¹⁶U
93	²²⁸Np
94	²²⁹Pu
95	²³⁰Am