出典:Wiktionary
出典:『Wiktionary』 (2026/04/24 23:22 UTC 版)
| Chemical element | ||||||||
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| Tc Atomic number 43 technetium |
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| Previous: ← molybdenum (Mo) | ||||||||
| Next: ruthenium (Ru) → | ||||||||
| English Wikipedia article on Technetium |
From Ancient Greek τεχνητός (tekhnētós, “artificial, manmade”) + -ium, because it was the first manmade element synthesized.
| Chemical element | ||||||||
|---|---|---|---|---|---|---|---|---|
| Tc Atomic number 43 technetium |
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| Previous: ← molybdaenum (Mo) | ||||||||
| Next: ruthenium (Ru) → |
出典:Wikipedia
出典:『Wikipedia』 (2011/06/19 07:41 UTC 版)
Technetium (
/tɛkˈniːʃiəm/ tek-nee-shee-əm) is the chemical element with atomic number 43 and symbol Tc. It is the lowest atomic number element without any stable isotopes; every form of it is radioactive. Nearly all technetium is produced synthetically and only minute amounts are found in nature. Naturally occurring technetium occurs as a spontaneous fission product in uranium ore or by neutron capture in molybdenum ores. The chemical properties of this silvery gray, crystalline transition metal are intermediate between rhenium and manganese.