A piece of cloth is discovered in a burial pit in the southwestern United States. A tiny sample of the cloth is burned to CO2, and the ¹4C/¹²C ratio is 0.250 times the ratio in today's atmosphere. How old is the cloth? The half-life of carbon-14, used in radiocarbon dating, is 5,730 years. O 11,500 years O 14,800 years O 12,600 years O 10,300 years

In a nuclear reactor, the excess neutrons produced from fission are absorbed by elements, preferably in solid form, which will not undergo fission when they absorb a neutron. From the table below, choose the best material to absorb neutrons in a nuclear reactor, and then explain your choice.   Half-lives of isotopes Isotope Half-Life (if unstable)  1H stable 2H stable 3H 12.3 years 12C stable 13C stable 14C 5730 years 27Al stable 28Al 2.25 minutes 209Bi stable 210Bi 5.01 days

A moon rock collected by a U.S. Apollo mission is estimated to be 4.00 billion years old by uranium/lead dating. Assuming that the rock did not contain any lead when it was formed, what is the current mass of Pb206 in the rock, if it currently contains 1.430 g of U238? The half-life of U238 is 4.47×109 years.

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