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NTA Abhyas JEE Main2020PhysicsNuclear PhysicsPractice

A radioactive sample of half-life 10 days, contains 1000 x nuclei. Number of original nuclei present after 5 days is

Options

  1. A707 x
  2. B750 x
  3. C500 x
  4. D250 x

Correct answer

A. 707 x

Step-by-step solution

The number of radioactive nuclei left after n half lives is N = N 0 2 n for 5 days n = 1 2 So, N = 1000 x 2 1 2 = 1000 x 2 = 1000 x 1.414 = 0.707 1000 x = 707 x

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