Question

A radioactive substance has a half-life of 5 years. What is the probability that a single atom of this substance will decay within 5 years?

• A. \( \frac{1}{2} \)
• B. \( \frac{1}{4} \)
• C. \( \frac{3}{4} \)
• D. \( \frac{1}{8} \)

Hint:

For radioactive decay, the probability that an atom decays in a given time period is related to the substance's half-life. In each half-life, half of the remaining atoms decay, so the probability of decay within one half-life is always \( \frac{1}{2} \).