Technetium
chemical element with symbol Tc and atomic number 43
Technetium is a chemical element; it has symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. Technetium is one of only two radioactive elements both preceded and succeeded in the periodic table by elements with stable forms, the other being promethium. All available technetium is produced as a synthetic element. Naturally occurring technetium is a spontaneous fission product in uranium ore and thorium ore (the most common source), or the product of neutron capture in molybdenum ores. This silvery gray, crystalline transition metal lies between manganese and rhenium in group 7 of the periodic table, and its chemical properties are intermediate between the two. The most common naturally occurring isotope is 99Tc, in traces only.
Many of technetium's properties had been predicted by Dmitri Mendeleev before it was discovered; Mendeleev noted a gap in his periodic table and gave the undiscovered element the provisional name ekamanganese (Em). In 1937, technetium became the first predominantly artificial element to be produced, hence its name (from the Greek technetos, 'artificial', + -ium).
One short-lived gamma-ray–emitting nuclear isomer, technetium-99m, is used in nuclear medicine for a wide variety of tests, such as bone cancer diagnoses.
This brief starts where responsible research should: with the source description of “Technetium” as chemical element with symbol Tc and atomic number 43. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the science & nature register because the source frames it as chemical element with symbol Tc and atomic number 43. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Datasets, specimens, observations and peer-reviewed methods provide the appropriate test for the technical claims summarized here. The source revision retrieved here is dated Sep 23, 2026. The linked authority identifier is Q1054. The Library of Congress control number is sh85133086. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1937.
A general summary may omit uncertainty, sample limits or methodological disagreement that is explicit in the technical record. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Technetium”, its source revision and the description used here.
- Expand the search: follow Technetium primary sources, Technetium archive and Technetium research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Technetium”?
- Which observation, specimen, dataset or publication supports the account?
- Is the terminology current, historical or disputed?
Search terms from this dossier
This entry incorporates text from “Technetium” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.