Technetium-91

Properties and data of the isotope ⁹¹Tc.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Technetium-91; Tc-91Symbol:⁹¹Tc or 9143TcMass number A:91 (= number of nucleons)Atomic number Z:43 (= number of protons)Neutrons N:48Isotopic mass:90.9184250(25) u (atomic weight of Technetium-91)Nuclide mass:90.8948372 u (calculated nuclear mass without electrons)Mass excess:-75.98662 MeVMass defect:0.83396734400002 u (per nucleus)Nuclear binding energy:776.83557713 MeV (per nucleus)
8.53665469 MeV (average binding energy per nucleon)Separation energy:S_N = 13.3333(26) MeV (first neutron)
S_P = 3.103(4) MeV (first proton)Half-life:3.14(2) minDecay constant λ:0.0036791251622078 s^-1Specific activity α:2.461801107572 × 10⁺¹⁹ Bq g^-1
665351650.69527 Ci g^-1Spin and parity:
(nuclear angular momentum)(9/2)+Year of discovery:1974

Radioactive Decay

Half-life T_½ = 3.14(2) min (minutes) respectively 1.884 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁹¹Mo	100 %	6.222(7) MeV

Parent Nuclides

Direct parent isotope is: ⁹¹Ru.

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
^91mTc	139.3(3) keV	3.3(1) min	(1/2)-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 48) and isobaric (same nucleon number A = 91) with Technetium-91. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 48	Isobar A = 91
26	⁷⁴Fe
27	⁷⁵Co
28	⁷⁶Ni
29	⁷⁷Cu
30	⁷⁸Zn
31	⁷⁹Ga
32	⁸⁰Ge
33	⁸¹As	⁹¹As
34	⁸²Se	⁹¹Se
35	⁸³Br	⁹¹Br
36	⁸⁴Kr	⁹¹Kr
37	⁸⁵Rb	⁹¹Rb
38	⁸⁶Sr	⁹¹Sr
39	⁸⁷Y	⁹¹Y
40	⁸⁸Zr	⁹¹Zr
41	⁸⁹Nb	⁹¹Nb
42	⁹⁰Mo	⁹¹Mo
43	⁹¹Tc	⁹¹Tc
44	⁹²Ru	⁹¹Ru
45	⁹³Rh	⁹¹Rh
46	⁹⁴Pd	⁹¹Pd
47	⁹⁵Ag
48	⁹⁶Cd
49	⁹⁷In
50	⁹⁸Sn