A half-life is the amount of time required ____.
A) to lose half the daughter isotopes
B) for the mass of the sample to decrease by one-half
C) for half of the parent atoms to decay to daughter atoms
D) for the parent atoms to increase by one-half
E) to accurately date a rock sample

Question

Quizplus · Accepted Answer

A half-life is the amount of time required for half of the parent atoms in a sample to decay into daughter atoms. It is not related to losing half the daughter isotopes or increasing the parent atoms by one-half. It may result in a decrease in the mass of the sample, but this is not the definition of half-life. Accuracy in dating a rock sample may depend on half-life, but this is not the primary definition.

A Half-Life Is the Amount of Time Required ____