Technetium-99
Properties and data of the isotope 99Tc.
See also: List of individual Technetium isotopes (and general data sources).
General data
Name of the isotope:Technetium-99; Tc-99Symbol:99Tc or 9943TcMass number A:99 (= number of nucleons)Atomic number Z:43 (= number of protons)Neutrons N:56Isotopic mass:98.9062497(10) u (atomic weight of Technetium-99)Nuclide mass:98.8826619 u (calculated nuclear mass without electrons)Mass excess:-87.32784 MeVMass defect:0.915461972 u (per nucleus)Nuclear binding energy:852.74733415 MeV (per nucleus)
8.61360944 MeV (average binding energy per nucleon)Separation energy:SN = 8.967(3) MeV (first neutron)
SP = 6.5009(9) MeV (first proton)Half-life:2.111(12) × 105 aDecay constant λ:1.041191453768 × 10-13 s-1Specific activity α:639816489.46484 Bq g-1
0.017292337553104 Ci g-1Spin and parity:
(nuclear angular momentum)9/2+Magnetic dipole moment:μ(μN) = +5.6847(4)Year of discovery:1938
Radioactive Decay
Half-life T½ = 2.111(12) × 105 a respectively 6.65725 × 1012 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| β- | 99Ru | 100 % | 0.2975(9) MeV | |
Parent Nuclides
Direct parent isotope is: 99Mo.
NMR data
Nuclear magnetic properties of the NMR active Nuclide 99Tc
Isotope:99Tc-NMRQuantity:Does not occur in nature!Spin:9/2+Nuclearmagnetic moment
μ/μN:+5.6847(4)Nuclear g-factor:gl = 1.2632666666667Quadrupole moment Q:- 0.129(6) barn (100 fm2)Resonance frequency:v0 = 9.6294 at 1 TRelative Sensitivity:0.38174 (H0 = const.)
7.4635 (v0 = const.)
[related to 1H = 1.000]
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 |
|---|
| 99mTc | 142.6836(11) keV | 6.0072(9) h | 1/2- |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 56) and isobaric (same nucleon number A = 99) with Technetium-99. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 56 | Isobar A = 99 |
|---|
| 31 | 87Ga | |
| 32 | 88Ge | |
| 33 | 89As | |
| 34 | 90Se | |
| 35 | 91Br | |
| 36 | 92Kr | 99Kr |
| 37 | 93Rb | 99Rb |
| 38 | 94Sr | 99Sr |
| 39 | 95Y | 99Y |
| 40 | 96Zr | 99Zr |
| 41 | 97Nb | 99Nb |
| 42 | 98Mo | 99Mo |
| 43 | 99Tc | 99Tc |
| 44 | 100Ru | 99Ru |
| 45 | 101Rh | 99Rh |
| 46 | 102Pd | 99Pd |
| 47 | 103Ag | 99Ag |
| 48 | 104Cd | 99Cd |
| 49 | 105In | 99In |
| 50 | 106Sn | 99Sn |
| 51 | 107Sb | |
| 52 | 108Te | |
| 53 | 109I | |
| 54 | 110Xe | |
External data and identifiers
Last update: 2023-05-22
Perma link: https://www.chemlin.org/isotope/technetium-99
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