A rock with only 25% of the parent isotope left has been decaying for time equal to ________ half-lives.
A. five
B. four
C. one
D. three
E. two
Answer: E
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Tectonic creep is the major cause of earthquakes in coastal California
Indicate whether the statement is true or false
Where do we find the youngest rocks in an eroded basin: near the center or near the flanks?
What will be an ideal response?
Suppose an electric-generating power plant is about to be built near your house. The local government has not decided whether to allow coal, nuclear, or oil as fuel for the plant (natural gas is not an option). Some groups argue coal is the best choice because there is a 200-year supply and using coal reduces our dependence on foreign oil. Critics argue that burning coal produces three times more global-warming gasses than oil. Coal also produces more dust and expels more acid-rain-causing gases than oil. Others argue that nuclear-generated power produces no greenhouse gases and no other atmospheric pollution. Critics argue that there is presently no long-term location to store the radioactive waste that will be generated and question the safety of nuclear power. Over the life of the
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Fossil evidence linking the Gondwana continents includes which animal fossils?
a. lake-dwelling Mesosaurus and large land-dwelling reptile Lystrosaurus and Cynognathus b. freshwater Mesosaurus and dinosaurs Brontosaurus and Tyrannosaurus c. freshwater crocodiles and the large amphibian Eryops d. reptile Dimetrodon and the first bird Archaeopteryx e. lake-dwelling Mesosaurus and the large land-dwelling reptiles Dimetrodon and Edaphosaurus