The radioactive element Unobtanium-189 (Ut-189) decays to the stable element Dilithium-171 (Di-171). The half-life of Ut-189 is 10 million years. Using a very sensitive atom-counter instrument, you determine that a mineral sample has 150 atoms of Di-171, and 50 atoms of Ut-189. Assume that no atoms have been lost due to metamorphism over the lifetime of the rock.Use this information to answer the following question.What is the age of the mineral?
A. 10 million years old
B. 20 million years old
C. 30 million years old
D. 40 million years old
Answer: B
You might also like to view...
Which of the following best describes most ecosystems?
A) They are sharply divided from other ecosystems. B) They consist of two or more distinct landscapes. C) They grade into other ecosystems in regions called ecotones. D) They are clustered with other ecosystems to form communities.
Compared to the rest of the planet, an unusually high concentration of hot spots and rifting is located on the continent of Africa. A likely explanation for this is that __________.
a) a large portion of Africa is located near the equator b) mantle plumes do not occur at divergent plate boundaries, and Africa has no divergent plate boundaries c) the African Plate is essentially stationary with respect to Earth's interior and the thick continental crust acts as a "heat blanket" d) the thick continental crust acts as a "heat blanket" and a large portion of Africa is located near the equator e) Africa is just very large
Large pig farms in North Carolina caused no pollution problems prior to the arrival of Hurricane Floyd
Indicate whether the statement is true or false
Which of the following animals living in Namibia is at the top of the food web?
A) Meerkat B) Stone grasshopper C) Oryx D) Lion