Technetium-90

Properties and data of the isotope ⁹⁰Tc.

Contents

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

General data

Name of the isotope:Technetium-90; Tc-90Symbol:⁹⁰Tc or 9043TcMass number A:90 (= number of nucleons)Atomic number Z:43 (= number of protons)Neutrons N:47Isotopic mass:89.9240739(11) u (atomic weight of Technetium-90)Nuclide mass:89.9004861 u (calculated nuclear mass without electrons)Mass excess:-70.72471 MeVMass defect:0.819653528 u (per nucleus)Nuclear binding energy:763.50234341 MeV (per nucleus)
8.48335937 MeV (average binding energy per nucleon)Separation energy:S_N = 11.40(4) MeV (first neutron)
S_P = 2.999(4) MeV (first proton)Half-life:49.2(4) sDecay constant λ:0.014088357328454 s^-1Specific activity α:9.532817114277 × 10⁺¹⁹ Bq g^-1
2576437057.9129 Ci g^-1Spin and parity:
(nuclear angular momentum)(8+)Year of discovery:1974

Radioactive Decay

Half-life T_½ = 49.2(4) s respectively 4.92 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁹⁰Mo	100 %	9.448(4) MeV

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
^90mTc	144.1(17) keV	8.7(2) s	1+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 47) and isobaric (same nucleon number A = 90) with Technetium-90. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 47	Isobar A = 90
26	⁷³Fe
27	⁷⁴Co
28	⁷⁵Ni
29	⁷⁶Cu
30	⁷⁷Zn
31	⁷⁸Ga
32	⁷⁹Ge	⁹⁰Ge
33	⁸⁰As	⁹⁰As
34	⁸¹Se	⁹⁰Se
35	⁸²Br	⁹⁰Br
36	⁸³Kr	⁹⁰Kr
37	⁸⁴Rb	⁹⁰Rb
38	⁸⁵Sr	⁹⁰Sr
39	⁸⁶Y	⁹⁰Y
40	⁸⁷Zr	⁹⁰Zr
41	⁸⁸Nb	⁹⁰Nb
42	⁸⁹Mo	⁹⁰Mo
43	⁹⁰Tc	⁹⁰Tc
44	⁹¹Ru	⁹⁰Ru
45	⁹²Rh	⁹⁰Rh
46	⁹³Pd	⁹⁰Pd
47	⁹⁴Ag
48	⁹⁵Cd
49	⁹⁶In