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∙ 16y ago1 ounce and three large testes
Wiki User
∙ 16y agoAfter the second half-life of uranium, half of the original amount will remain. Therefore, if you start with 80 grams of uranium, after one half-life you would have 40 grams remaining, and after the second half-life, you would have 20 grams.
This affirmation is not correct; the half lives are different.
The half-life of uranium-235 is approximately 703.8 million years, while the half-life of uranium-238 is approximately 4.5 billion years.
Half life is the time taken for half the atoms to decay. Whatever mass you start with, if it is a sample consisting of one pure uranium isotope, you will have half that mass of uranium after one half life. The piece of metal will not weigh half of the original mass, because the decay products will be there. In practice, a piece of uranium usually consists of a mixture of isotopes with different half lives.
Since the element has a half-life of 1000 years, it will take two half-lives for the mass to decrease to 5 grams from 20 grams. Two half-lives equal 2000 years, so you would have to wait 2000 years for the mass to decrease to 5 grams.
If a radioactive isotope has a half-life of 4 years, than 0.125 (0.53) of the isotope will remain after 12 years, or 3 half-lives.The question asked about Uranium. There is no isotope of Uranium with a half-life of 4 years. The closest is 232U92, which has a half-life of 68.9 years.Reference: http://www.nndc.bnl.gov/chart/
To calculate the amount of thorium remaining after 2 half-lives, you use the formula: amount = initial amount * (1/2)^n, where n is the number of half-lives. If we assume the initial amount is 1 gram, after 2 half-lives, there would be 0.25 grams of thorium remaining.
Half life is the time taken for half the atoms to decay. Whatever mass you start with, if it is a sample consisting of one pure uranium isotope, you will have half that mass of uranium after one half life. The piece of metal will not weigh half of the original mass, because the decay products will be there. In practice, a piece of uranium usually consists of a mixture of isotopes with different half lives.
The decay of plutonium-240 has a half-life of about 656 million years. To go from 36 grams to 12 grams would require two half-lives, so it would take approximately 1.3 billion years for 36 grams of plutonium-240 to decay to 12 grams.
You would have to wait for 2000 years for the mass to decrease to 50 grams (one half-life) and another 2000 years to decrease to 25 grams (two half-lives). So, in total, you would have to wait 4000 years for the mass to decrease to 25 grams.
It would take 51 days for 32 grams of palladium-103 to decay to 2.0 grams. This calculation involves multiple half-lives, as every 17 days half of the remaining material decays. By dividing the initial mass by 2 repeatedly until you reach 2.0 grams, you find that it takes 3 half-lives for the decay to occur.
Uranium-lead dating would be the best technique for dating volcanic rock containing uranium. This method is commonly used for dating ancient rocks due to the long half-lives of uranium isotopes and the presence of lead isotopes as decay products that allow for precise age determination.