Chapter 1

How much of the parent isotope would be remaining after 7 half-lives have passed? a. $6.25\mathrm{\%}$ b. $1.56\mathrm{\%}$ c. $0.78\mathrm{\%}$ d. $0.39\mathrm{\%}$

If a radiometric element has a half-life of 425 years, how old would a rock be that only had $3.125\mathrm{\%}$ of the parent isotope remaining? a. 2125 years b. 1700 years c. 2550 years d. 3400 years

Using what you learned in the previous section regarding absolute dating, determine the most appropriate methods and the ages of the materials in the following question .An Archeologist finds some cotton cloth at a burial site and wants to determine the age of the remains. Which isotopic system should they use? a. Carbon-14 b. Uranium c. Potassium-Argon