The first element that doesn't exist in nature. Technetium was created artificially in 1937 by bombarding molybdenum with particles in a cyclotron. All of its isotopes are radioactive. Even the most stable one lasts only 4.2 million years — a blink of an eye on Earth's timescale.
But this very radioactivity made technetium indispensable in medicine. The isotope Tc-99m emits soft gamma rays, perfect for scanning organs. Over 30 million patients undergo technetium diagnostics each year. It's the most widely used radioactive drug in the world.
Technetium is a transition metal with a density of 11 g/cm³. It's silvery-gray and quite hard. It melts at 2,430 K — higher than iron. Chemically, it resembles rhenium and manganese.
Its most fascinating property is anti-corrosion. Adding just 55 parts per million of technetium to steel makes it virtually immune to rust. But due to radioactivity, this property isn't used commercially. Technetium remains purely a medical and research element.
Technetium is radioactive. All its isotopes emit ionizing radiation. Tc-99m has a short half-life (6 hours) and low gamma-ray energy, making it safe for diagnostics. But Tc-99 lasts 211,000 years and can accumulate in the thyroid gland. Working with technetium is permitted only in licensed radiological facilities with proper radiation protection measures.
Technetium was the first artificially created element. Before 1937, cell 43 in the periodic table sat empty for nearly 70 years.
Over 30 million medical procedures use Tc-99m every year. That's 80% of all nuclear medicine imaging worldwide.
The Tc-99m isotope lives only 6 hours. Within a day, its radioactivity drops 16-fold — the body clears it quickly.
Adding 55 parts per million of technetium makes steel virtually immune to corrosion. Too bad it's radioactive.
The name means 'artificial' — from Greek technetos. It's the only element named after technology, not a place or scientist.
In 1952, technetium was found in the spectra of distant stars. This proved that stars constantly forge new elements.
| Isotope | Mass (u) | Abundance | Half-life | Decay |
|---|---|---|---|---|
97Tc☢ | 96.906365 | synthetic | 4.21×10⁶ years | EC |
98Tc☢ | 97.907216 | synthetic | 4.2×10⁶ years | β− |
99Tc☢ | 98.906255 | synthetic | 2.111×10⁵ years | β− |
Cyclotron bombardment of molybdenum