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Aim: How to solve half-life problems?. Do Now : 1) What fraction of an original sample of a radioactive isotope remains after three half lives? Half life graph Half-life - time it takes for half a sample of a particular radioactive isotope to decay; the rate of nuclear decay.
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Aim: How to solve half-life problems? Do Now: 1) What fraction of an original sample of a radioactive isotope remains after three half lives? Half life graph • Half-life- time it takes for half a sample of a particular radioactive isotope to decay; the rate of nuclear decay. • Half-life is a constant value and is not affected by • temperature or pressure. • The use of radioactive isotopes to determine the age of an object is called radioactive dating.
Aim: How to solve half-life problems Essential questions: • How many half-lives of radon-222 have passed in 11.46 days? • If 5.2 x 10-8 g of radon-222 remain in a sealed box after 11.46 days, how much was present in the box initially? • Explain how carbon-14 is used to determine the age of an object. • Why is potassium-40 used to date ancient rocks and minerals? • Why is uranium-235 considered to be a greater health threat than radon-222? • Identify three practical applications of nuclear chemistry.