Physics Nuclear Physics ETEA 2022
PMDC Verified Question 34 of 98
The half-life of a radio-active sample predicts about:
A
Whole life of sample
B
Disintegration time of half number of atoms
C
Decay only
D
Total time for stable atoms
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Disintegration time of half number of atoms


Concept:

This question tests the strict definition of radioactive half-life.

Solution:

  • Half-life (\(T_{1/2}\)) is defined as the exact interval of time required for half of the unstable parent nuclei in a given sample to undergo radioactive disintegration.


  • Because decay is statistical, you can never predict exactly which atom will decay, but you can confidently predict that 50% of the entire population will transform over this time period.


Why other options are incorrect:

A radioactive sample technically takes an infinite time to decay completely, so "whole life" is meaningless. Option C is too vague. Option D does not define the rate at which they stabilize.

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