Technetium
Technetium (Tc) is element 43, a transition metal in group 7, period 5. The mass of its longest-lived isotope is 96.90636 u. It is a solid at room temperature and melts at 2156.85 °C. Its electron configuration is [Kr] 5s² 4d⁵.
Technetium holds a unique place on the periodic table: it was the first element ever created artificially rather than found in nature, and every one of its isotopes is radioactive. Despite that, one of its forms has become one of the most important tools in modern medicine.
- Group · Period
- 7 · 5
- At room temp
- solid
- Melts at
- 2430 K
- Density
- 11 g/cm³
- Discovered
- 1937
Key facts about technetium
Quick answers, built from the sourced data in the property tables.
- What is the electron configuration of technetium?
- The electron configuration of technetium is [Kr] 5s² 4d⁵. Written out in full, that is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 5s² 4d⁵.
- What is the density of technetium?
- The density of technetium is 11 g/cm³.
- What are the melting and boiling points of technetium?
- Technetium melts at 2430 K (2156.85 °C, 3914.33 °F) and boils at 4538 K (4264.85 °C, 7708.73 °F).
- What is the electron affinity of technetium?
- The electron affinity of technetium is 0.55 eV, which is about 53.1 kJ/mol.
- What is the longest-lived isotope of technetium?
- Technetium has no stable isotopes. Its longest-lived known isotope is Tc-97, with a half-life of 4.21 × 10⁶ years.
Uses
Technetium’s overwhelming real-world importance is in medicine. The isotope technetium-99m emits a form of radiation that’s easy to detect externally, decays away quickly, and can be attached to different carrier molecules that target specific organs or tissues. Injected in small, carefully calculated doses, it’s used in a huge share of nuclear medicine imaging scans worldwide, helping doctors examine bone health, heart function, and other conditions without invasive procedures.
Outside medicine, technetium has essentially no practical use. Because every isotope is radioactive, it’s produced only in the small quantities needed for research and healthcare, and it plays no role in construction, manufacturing or everyday products the way many other transition metals do.
History
Technetium’s existence was actually predicted decades before it was found, since Mendeleev’s periodic table left a gap for an undiscovered element between molybdenum and ruthenium. Several premature discovery claims were made and later disproven, until 1937, when Italian physicists Carlo Perrier and Emilio Segrè examined a sample of molybdenum that had been bombarded with deuterons in Ernest Lawrence’s cyclotron at Berkeley. They identified a new element that hadn’t been extracted from any natural source but had instead been created directly through nuclear reactions. They named it technetium, from the Greek word technetos, meaning artificial, marking it as the first element in history to be made by humans before ever being found in nature.
Fun facts
- Technetium was the first element to be produced artificially rather than discovered in nature, made in a particle accelerator in 1937.
- Its name comes from the Greek word 'technetos,' meaning artificial, a direct reference to how it was created.
- No isotope of technetium is stable — every form of the element is radioactive, which is why it's essentially absent from the natural world.
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Frequently asked questions
Does technetium occur naturally on Earth at all?
Only in extraordinarily tiny, fleeting traces, produced when uranium ore spontaneously undergoes fission deep underground. For practical purposes, essentially all the technetium used today is manufactured, which is what makes it so unusual among the elements.
Why isn't technetium used in construction or industry like other metals?
Because it's radioactive, synthetic and expensive to produce, technetium has no meaningful structural or industrial role — it would be both impractical and hazardous to use in bulk. Its value lies almost entirely in the tiny, carefully controlled quantities used for medical purposes.
What is technetium actually used for, then?
Its main real-world application is in medicine, specifically the isotope technetium-99m, which is injected in small, safe amounts as a tracer for diagnostic imaging. Its radiation is detected by a gamma camera to reveal how organs and tissues, such as the heart, bones or kidneys, are functioning.
Compounds
3 notable compounds containing Tc
- NaTcO4salt
Sodium pertechnetate
A water-soluble salt containing technetium-99m that is eluted directly from hospital technetium generators and injected as the workhorse radioactive tracer of nuclear medicine.
Used for: Most widely used radioactive tracer for diagnostic imaging (thyroid and bone scans)
- TcO2oxide
Technetium dioxide
A dark, insoluble oxide of technetium formed when pertechnetate is reduced, relevant to how technetium behaves in nuclear waste and reactor environments.
Used for: Studied in nuclear waste chemistry for technetium's environmental behavior
- Tc2O7oxide
Technetium heptoxide
A yellow, volatile solid that is the highest oxide of technetium, formed by burning the metal in oxygen, and dissolves in water to give pertechnetic acid.
Used for: Laboratory intermediate for preparing other technetium compounds
Isotopes
38 known isotopes
Swipe to see all columns →
| Isotope | Natural abundance | Half-life | Decay mode | Mass excess | Binding energy / nucleon | Decay width | Spin/parity | Magnetic moment | Quadrupole moment |
|---|---|---|---|---|---|---|---|---|---|
| Tc-97 | — | 4.21E+6 Y | Electron capture (100%) | -87,224.44 keV | 8,623.73 keV | 3.43 × 10-30 eV | 9/2+ | 5.82 μN | — |
| Tc-98 | — | 4.2E+6 Y | Beta-minus decay (100%) | -86,432.21 keV | 8,610 keV | 3.44 × 10-30 eV | (6)+ | — | — |
| Tc-99 | — | 2.111E+5 Y | Beta-minus decay (100%) | -87,327.87 keV | 8,613.61 keV | 6.85 × 10-29 eV | 9/2+ | 5.678 μN | -0.129 b |
| Tc-85 | — | 100 ns | Proton emission | -45,850 keV | 8,215 keV | 4.56 × 10-9 eV | — | — | — |
| Tc-86 | — | 55 ms | Electron capture / beta-plus decay (100%), ECP | -51,570 keV | 8,280 keV | 8.30 × 10-15 eV | (0+) | — | — |
| Tc-87 | — | 2.2 s | Electron capture / beta-plus decay (100%) | -57,690.05 keV | 8,347.74 keV | 2.07 × 10-16 eV | (9/2+) | — | — |
| Tc-88 | — | 6.4 s | Electron capture / beta-plus decay (100%), ECP | -61,670.3 keV | 8,389.83 keV | 7.13 × 10-17 eV | (5+ 6+ 7+) | — | — |
| Tc-89 | — | 12.8 s | Electron capture / beta-plus decay (100%) | -67,394.86 keV | 8,450.58 keV | 3.56 × 10-17 eV | (9/2+) | — | — |
| Tc-90 | — | 49.2 s | Electron capture (100%) | -70,724.7 keV | 8,483.36 keV | 9.27 × 10-18 eV | (8+) | — | — |
| Tc-91 | — | 3.14 m | Electron capture / beta-plus decay (100%) | -75,986.66 keV | 8,536.66 keV | 2.42 × 10-18 eV | (9/2)+ | — | — |
| Tc-92 | — | 4.25 m | Electron capture / beta-plus decay (100%) | -78,925.7 keV | 8,563.54 keV | 1.79 × 10-18 eV | (8)+ | — | — |
| Tc-93 | — | 2.75 h | Electron capture / beta-plus decay (100%) | -83,606.12 keV | 8,608.58 keV | 4.61 × 10-20 eV | 9/2+ | 6.32 μN | — |
| Tc-94 | — | 293 m | Electron capture / beta-plus decay (100%) | -84,158.33 keV | 8,608.74 keV | 2.60 × 10-20 eV | 7+ | 5.12 μN | — |
| Tc-95 | — | 20.0 h | Electron capture / beta-plus decay (100%) | -86,021.36 keV | 8,622.69 keV | 6.34 × 10-21 eV | 9/2+ | 5.94 μN | — |
| Tc-96 | — | 4.28 d | Electron capture / beta-plus decay (100%) | -85,821.65 keV | 8,614.87 keV | 1.23 × 10-21 eV | 7+ | 5.09 μN | — |
| Tc-100 | — | 15.65 s | Beta-minus decay (99.9974%), Electron capture (0.0026%) | -86,020.95 keV | 8,595.12 keV | 2.92 × 10-17 eV | 1+ | — | — |
| Tc-101 | — | 14.22 m | Beta-minus decay (100%) | -86,344.59 keV | 8,593.14 keV | 5.35 × 10-19 eV | 9/2+ | — | — |
| Tc-102 | — | 5.28 s | Beta-minus decay (100%) | -84,572.92 keV | 8,570.65 keV | 8.64 × 10-17 eV | 1+ | — | — |
| Tc-103 | — | 54.2 s | Beta-minus decay (100%) | -84,603.92 keV | 8,566.1 keV | 8.42 × 10-18 eV | 5/2+ | — | — |
| Tc-104 | — | 18.3 m | Beta-minus decay (100%) | -82,498.97 keV | 8,541.11 keV | 4.16 × 10-19 eV | (3+) | — | — |
| Tc-105 | — | 7.64 m | Beta-minus decay (100%) | -82,286.3 keV | 8,534.61 keV | 9.95 × 10-19 eV | (3/2-) | — | — |
| Tc-106 | — | 35.6 s | Beta-minus decay (100%) | -79,776.25 keV | 8,506.56 keV | 1.28 × 10-17 eV | (1 2) | — | — |
| Tc-107 | — | 21.2 s | Beta-minus decay (100%) | -78,749.97 keV | 8,492.9 keV | 2.15 × 10-17 eV | (3/2-) | — | — |
| Tc-108 | — | 5.17 s | Beta-minus decay (100%) | -75,922.83 keV | 8,462.82 keV | 8.82 × 10-17 eV | (2)+ | — | — |
| Tc-109 | — | 0.91 s | Beta-minus decay (100%), Beta-minus, neutron emission (0.08%) | -74,282.83 keV | 8,444.18 keV | 5.01 × 10-16 eV | (5/2+) | — | — |
| Tc-110 | — | 0.900 s | Beta-minus decay (100%), Beta-minus, neutron emission (0.04%) | -71,034.56 keV | 8,411.26 keV | 5.07 × 10-16 eV | (2 3+) | — | — |
| Tc-111 | — | 290 ms | Beta-minus decay (100%), Beta-minus, neutron emission (0.85%) | -69,024.68 keV | 8,390.09 keV | 1.57 × 10-15 eV | (5/2+) | — | — |
| Tc-112 | — | 271 ms | Beta-minus decay (100%), Beta-minus, neutron emission (1.5%) | -65,258.93 keV | 8,353.62 keV | 1.68 × 10-15 eV | (2+) | — | — |
| Tc-113 | — | 152 ms | Beta-minus decay (100%), Beta-minus, neutron emission (2.1%) | -62,811.55 keV | 8,329.47 keV | 3.00 × 10-15 eV | (5/2+) | — | — |
| Tc-114 | — | 100 ms | Beta-minus decay (100%), Beta-minus, neutron emission | -58,600.29 keV | 8,290.26 keV | 4.56 × 10-15 eV | (GE 4) | — | — |
| Tc-115 | — | 78 ms | Beta-minus decay (100%), Beta-minus, neutron emission | -55,796 keV | 8,264 keV | 5.85 × 10-15 eV | — | — | — |
| Tc-116 | — | 57 ms | Beta-minus decay (100%), B-2N, Beta-minus, neutron emission | -51,214 keV | 8,223 keV | 8.00 × 10-15 eV | — | — | — |
| Tc-117 | — | 44.5 ms | Beta-minus decay (100%), Beta-minus, neutron emission, B-2N | -48,140 keV | 8,195 keV | 1.03 × 10-14 eV | — | — | — |
| Tc-118 | — | 30 ms | Beta-minus decay (100%), Beta-minus, neutron emission, B-2N | -43,290 keV | 8,153 keV | 1.52 × 10-14 eV | — | — | — |
| Tc-119 | — | 22 ms | Beta-minus decay (100%), Beta-minus, neutron emission, B-2N | -40,170 keV | 8,126 keV | 2.07 × 10-14 eV | — | — | — |
| Tc-120 | — | 21 ms | Beta-minus decay (100%), B-2N, Beta-minus, neutron emission | -35,000 keV | 8,083 keV | 2.17 × 10-14 eV | — | — | — |
| Tc-121 | — | 22 ms | Beta-minus decay (100%), Beta-minus, neutron emission, B-2N | -31,540 keV | 8,054 keV | 2.07 × 10-14 eV | — | — | — |
| Tc-122 | — | — | Beta-minus decay (100%), Beta-minus, neutron emission, B-2N | -26,305 keV | 8,011 keV | — | — | — | — |
Spin/parity describes the nucleus's intrinsic angular momentum and symmetry. Magnetic moment (in nuclear magnetons, μN) and quadrupole moment (in barns, b) describe the shape of the nucleus's charge distribution — a nonzero quadrupole moment means the nucleus isn't perfectly spherical. These are only measured for a subset of isotopes, mostly stable or long-lived ones, so many rows show "—" rather than a value.