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MHT CET202122 Sep 2021Evening ShiftChemistryd and f Block ElementsActual

Which element from following is radioactive?

Options

  1. APr
  2. BNd
  3. CPm
  4. DSm

Correct answer

C. Pm

Step-by-step solution

Promethium is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is extremely rare, with only about 500-600 grams naturally occurring in Earth's crust at any given time.

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