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JAMB Physics 1992 Question 49

Question 49

Radioactivity and Nuclear Physics

After three half lifes, the fraction of a radioactive material that has decayed is

  1. A.1/8
  2. B.1/3
  3. C.2/3
  4. D.7/8
Show the answer and explanation

Answer: D (7/8)

Explanation

After three half-lives ½ × ½ × ½ = 1/8 remains, so 1 − 1/8 = 7/8 has decayed.