The Half-Life of a Radioactive Substance Is 5 Min

Multiple Choice

The half-life of a radioactive substance is 5 min.Which of the following statements is true of the decay of this substance?

A) After 10 min,one-fourth of the original substance remains.
B) The amount of the substance remaining after a given time is proportional to the number of minutes.
C) The amount of the substance remaining after a given time is inversely proportional to the number of minutes.
D) After 10 min,none of the original substance remains unchanged.
E) None of these is correct.