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Q117 (IAS/2001) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Periodic table elements Answer Verified

Which one of the following is NOT radioactive ?

Result
Your answer: —  Â·  Correct: D
Explanation

Correct answer: Zirconium (4). Zirconium (Z=40) is not inherently radioactive because it lies among the first 82 elements, which each have at least one stable isotope; elements below Z=82 therefore include many stable elements, and zirconium has several stable isotopes [1]. In contrast, astatine (Z=85) and francium (Z=87) are beyond lead (Z=82) and are known to have only unstable (radioactive) isotopes, so they are radioactive [1]. Tritium (hydrogen-3) is a radioactive isotope of hydrogen (a beta emitter) and can be produced as an activation product in reactors [2]. Thus zirconium is the non‑radioactive choice among the options.

Sources

  1. [1] https://sciencenotes.org/what-are-the-radioactive-elements/
  2. [2] https://www.eesi.org/files/GE_Congress_2021.pdf
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