Physics Nuclear Physics ETEA 2022
PMDC Verified Question 36 of 98
Radioactivity does not depend upon:
A
Initial number of atoms
B
Temperature
C
Nature of material
D
Time
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Temperature


Concept:

Radioactivity is an internal property of atomic nuclei, governed by the strong and weak nuclear forces, which operate on enormous energy scales.

Solution:

  • The rate of decay (Activity, \(A\)) depends mathematically on the initial number of atoms (\(N_0\)), the nature of the material (decay constant \(\lambda\)), and the passage of time (\(t\)).


  • Macroscopic environmental factors like temperature, pressure, and chemical bonding possess energy levels in the electron-volts (eV) range, which are utterly insufficient to penetrate or influence the nucleus (MeV range).


  • Therefore, heating or freezing a radioactive material has zero effect on its half-life or decay rate.


Why other options are incorrect:

Activity explicitly depends on \(N_0\), material type, and time elapsed via the formula \(A = A_0 e^{-\lambda t}\).

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