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MDCAT
Physics
2021

Physics · Nuclear Physics

Work through this past-paper style MCQ, then read the full explanation. Practice more physics questions on mMCQ with adaptive practice and topic analytics.

Question

Half-life of radioactive element means:

Options
  • A

    Full life decay

  • B

    Quarter life decay

  • C

    Time for half of the element to decay

  • D

    All of these options are correct

Explanation

Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay. This also implies that one half life is the time that it takes for the activity of a source to fall to half its original value. 

Option (a) "Full life decay" is not correct. The term "full life decay" is not a standard concept in the context of radioactive decay. The correct term is "half-life," which refers to the time it takes for half of the radioactive atoms in a sample to decay. 

Option (b) "Quarter life decay" is also not correct. The concept of "quarter life decay" is not used in radioactive decay. The relevant term is still "half-life," which indicates the time taken for half of the radioactive atoms to decay. 

Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay. This also implies that one half life is the time that it takes for the activity of a source to fall to half its original value. 

Option (d) is not correct because only option (c) is the accurate explanation of the half-life of a radioactive element. The concept of "half-life" specifically refers to the time it takes for half of the radioactive atoms to decay and not any other fraction like "full life decay" or "quarter life decay." 

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Tagged under Physics · Nuclear Physics · 2021