engineering chemistry MCQ #4899

The half-life of a radioactive substance is 20 years. What fraction remains after 1 / 2 40 years?

engineering chemistry MCQ #4899

  1. Question 1

    Q1. The half-life of a radioactive substance is 20 years. What fraction remains after 1 / 2 40 years?

    • A) 1/4
    • B) 1/2
    • C) 1/8
    • D) 1/16

    Answer: 1/16

    Explanation: After 20 years, 1/2 remains; after 40 years, 1/4; after 60 years, 1/8; after 80 years (2 * 40 years), 1/16 remains.