Question

One half-life of a radioactive isotope has passed when:

a. all the parent nuclei have become daughter nuclei.
b. the number of daughter nuclei is twice the number of parent
nuclei.
c. the number of daughter nuclei is half the number of parent nuclei.
d. the numbers of parent and daughter nuclei are equal.

Answer 1

C the number of daughter nuclei is half the number of parent nuclei.