Radioactivity decay: An isotope has a half-life of 2 hours. What fraction remains after 6 hours? Assume simple first-order decay. Choose the correct remaining fraction.

IIT JEE Chemistry Difficulty: Easy
Choose an option
  • A
    1/2
  • B
    1/4
  • C
    1/8
  • D
    1/16

Answer

Correct Answer: 1/8

Explanation

Given

  • Half-life t1/2 = 2 h; elapsed time t = 6 h.

CalculationNumber of half-lives = t / t1/2 = 6/2 = 3.Remaining fraction = (1/2)3 = 1/8 = 0.125.

Final Answer1/8 of the initial quantity remains.

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