Thallium-210

Properties and data of the isotope ²¹⁰Tl.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Thallium-210; Tl-210Symbol:²¹⁰Tl or 21081TlMass number A:210 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:129Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.5925925925926 (= neutron-proton ratio)Neutron excess (N-Z):48Isotopic mass:209.990073(12) u (atomic weight of Thallium-210)Nuclide mass:209.945643 u (calculated nuclear mass without electrons)Mass excess:-9.24694 MeVMass defect:1.761528756 u (per nucleus)Nuclear binding energy:1640.85346704 MeV (per nucleus)
7.81358794 MeV (average binding energy per nucleon)Separation energy:S_N = 3.674(13) MeV (first neutron)
S_P = 7.89(15) MeV (first proton)Half-life:1.30(3) minDecay constant λ:0.0088865023148711 s^-1Specific activity α:2.560563095325 × 10⁺¹⁹ Bq g^-1
692044079.81776 Ci g^-1Spin and parity:
(nuclear angular momentum)(5+)Year of discovery:1909

Radioactive Decay

Half-life T_½ = 1.30(3) min (minutes) respectively 7.8 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²¹⁰Pb	99.993 %	5.482(12) MeV
β^-, n	²⁰⁹Pb	0.007 %	0.296(12) MeV

Parent Nuclides

Direct parent isotope is: ²¹⁴Bi.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 129) and isobaric (same nucleon number A = 210) with Thallium-210. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 129	Isobar A = 210
78	²⁰⁷Pt
79	²⁰⁸Au	²¹⁰Au
80	²⁰⁹Hg	²¹⁰Hg
81	²¹⁰Tl	²¹⁰Tl
82	²¹¹Pb	²¹⁰Pb
83	²¹²Bi	²¹⁰Bi
84	²¹³Po	²¹⁰Po
85	²¹⁴At	²¹⁰At
86	²¹⁵Rn	²¹⁰Rn
87	²¹⁶Fr	²¹⁰Fr
88	²¹⁷Ra	²¹⁰Ra
89	²¹⁸Ac	²¹⁰Ac
90	²¹⁹Th	²¹⁰Th
91	²²⁰Pa	²¹⁰Pa
92	²²¹U
93	²²²Np