Cesium-137 is part of the nuclear waste produced by uranium-235 fission. The half-life of cesium-137 is 30.2 years. How much time is required for the activity of a sample of cesium-137 to fall to 25.1 percent of its original value?

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asked by chan
  1. ln(100/25.1) = kt
    k = 0.693/t1/2

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