A rock contains 18 mg of the radioactive isotope carbon-14. The half-life of carbon-14 is 5,600 years. How many half-lives and years will it take before the carbon-14 decays to less than 4 mg?
A. 1 half-lives; 5,600 years
B. 2 half-lives; 11,200 years
C. 4 half-lives; 22,400 years
D. 9 half-lives; 50,400 years
E. 3 half-lives; 16,800 years
Answer: E
You might also like to view...
Fermentation is a process that proceeds without oxygen. Such a process can be described as ________.
Fill in the blank(s) with the appropriate word(s).
You and your biology lab class take a field trip to a marine aquarium. Your guide is a marine biologist who studies squids. She explains to your class how squids are able to blend into their environment. She points out that squids have pouches of pigments embedded in their epithelium. The pouches are called
A. trochophores. B. spermatophores. C. lophophores. D. chromatophores. E. phytophores.
Primary growth (lengthening) arises from ____________________. Fill in the blank(s) with the appropriate word(s)
Which of the following is not a protective behavior that will help prevent cancer?
A. Avoid radiation. B. Increase consumption of salt-cured, smoked, and nitrite-cured foods. C. Increase consumption of vegetables from the cabbage family. D. Don't sunbathe. E. Don't use tobacco.