Half-Life :Half-Life Time it takes for half of a radioactive sample to decay Describes rate of decay Less stable - faster decay


Half-Life Visual :Half-Life Visual After each half-life, half of the sample changes. START 100%


Half-Life Visual :Half-Life Visual After each half-life, half of the sample changes. START 100% 1 half-life 50% 50% transmutes into another element


Half-Life Visual :Half-Life Visual After each half-life, half of the sample changes. START 100% 1 half-life 50% 2 half-lives 25% 50% of the 50% then transmutes into another element


Half-Life Visual :Half-Life Visual After each half-life, half of the sample changes. START 100% 1 half-life 50% 2 half-lives 25% 3 half-lives 12.5% 50% of the 25% then transmutes into another element This leaves 12.5%


Half-Life Visual :Half-Life Visual After each half-life, half of the sample changes. START 100% 1 half-life 50% 2 half-lives 25% 3 half-lives 12.5% 4 half-lives 6.25%


Half-Life Visual :Half-Life Visual After each half-life, half of the sample changes. START 100% 1 half-life 50% 2 half-lives 25% 3 half-lives 12.5% 4 half-lives 6.25% 5 half-lives 3.125%


Half-Life Visual :Half-Life Visual After each half-life, half of the sample changes. START 100% 1 half-life 50% 2 half-lives 25% 3 half-lives 12.5% 4 half-lives 6.25% 5 half-lives 3.125% 6 half-lives 1.5625%


Half-Life Visual :Half-Life Visual After each half-life, half of the sample changes. START 100% 1 half-life 50% 2 half-lives 25% 3 half-lives 12.5% 4 half-lives 6.25% 5 half-lives 3.125% 6 half-lives 1.5625% 7 half-lives .78125%


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay) 83Bi  -1e + ?? 210 0 ?


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay) 83Bi  -1e + ?? 210 0 210


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay) 83Bi  -1e + 84? 210 0 210


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay) 83Bi  -1e + 84Po 210 0 210


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210)


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5 0.25 g Bi-210 0.75 g Po-210 day 10


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5 0.25 g Bi-210 0.75 g Po-210 day 10 0.12 g Bi-210 0.88 g Po-210 day 15


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5 0.25 g Bi-210 0.75 g Po-210 day 10 0.12 g Bi-210 0.88 g Po-210 day 15 0.062 g Bi-210 0.94 g Po-210 day 20


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5 0.25 g Bi-210 0.75 g Po-210 day 10 0.12 g Bi-210 0.88 g Po-210 day 15 0.062 g Bi-210 0.94 g Po-210 day 20 0.031 g Bi-210 0.97 g Po-210 day 25


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5 0.25 g Bi-210 0.75 g Po-210 day 10 0.12 g Bi-210 0.88 g Po-210 day 15 0.062 g Bi-210 0.94 g Po-210 day 20 0.031 g Bi-210 0.97 g Po-210 day 25 0.016 g Bi-210 0.99 g Po-210 day 30


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5 0.25 g Bi-210 0.75 g Po-210 day 10 0.12 g Bi-210 0.88 g Po-210 day 15 0.062 g Bi-210 0.94 g Po-210 day 20 0.031 g Bi-210 0.97 g Po-210 day 25 0.016 g Bi-210 0.99 g Po-210 day 30 0.0080 g Bi-210 0.99 g Po-210 day 35


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5 0.25 g Bi-210 0.75 g Po-210 day 10 0.12 g Bi-210 0.88 g Po-210 day 15 0.062 g Bi-210 0.94 g Po-210 day 20 0.031 g Bi-210 0.97 g Po-210 day 25 0.016 g Bi-210 0.99 g Po-210 day 30 0.0080 g Bi-210 0.99 g Po-210 day 35 0.0040 g Bi-210 0.99 g Po-210 day 40


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5 0.25 g Bi-210 0.75 g Po-210 day 10 0.12 g Bi-210 0.88 g Po-210 day 15 0.062 g Bi-210 0.94 g Po-210 day 20 0.031 g Bi-210 0.97 g Po-210 day 25 0.016 g Bi-210 0.99 g Po-210 day 30 0.0080 g Bi-210 0.99 g Po-210 day 35 0.0040 g Bi-210 0.99 g Po-210 day 40 0.0020 g Bi-210 0.99 g Po-210 day 45


Half-Life Again :Half-Life Again 1.00 g of Bi-210 (beta decay to Po-210) 0.50 g Bi-210 0.50 g Po-210 day 5 0.25 g Bi-210 0.75 g Po-210 day 10 0.12 g Bi-210 0.88 g Po-210 day 15 0.062 g Bi-210 0.94 g Po-210 day 20 0.031 g Bi-210 0.97 g Po-210 day 25 0.016 g Bi-210 0.99 g Po-210 day 30 0.0080 g Bi-210 0.99 g Po-210 day 35 0.0040 g Bi-210 0.99 g Po-210 day 40 0.0020 g Bi-210 0.99 g Po-210 day 45 0.0010 g Bi-210 0.99 g Po-210 day 50


?Safe Samples? :?Safe Samples? Each half-life reduces amount of radioisotope Amount never becomes zero After 10 half-lives sample considered nonradioactive


Uses of Radioisotopes :Uses of Radioisotopes Radioactive Dating Nuclear Medicine Food Preservation


Radioactive Dating :Radioactive Dating Estimates age of very old objects Uses carbon-14 Possible other isotopes Uranium - 235 Potassium - 40 Samarium - 147


Radiocarbon Dating :Radiocarbon Dating Half-life 5730 years Found in all living things Tiny amount Compare to amount carbon-12 Living organisms maintain carbon-14 After dying, carbon-14 decays


Nuclear Medicine :Nuclear Medicine X-rays Radiotracers Radiotherapy


Nuclear Medicine :Nuclear Medicine X-rays Image inside the body CAT Different angles Injuries related to head or brain


Nuclear Medicine :Nuclear Medicine X-rays Radiotracers Tiny amount of radioisotope Path traced through body Short half-life


Nuclear Medicine :Nuclear Medicine X-rays Radiotracers Radiotherapy Direct beam at specific area with cancer Fast growing cells vulnerable


Food Preservation :Food Preservation Fresh foods susceptible to mold or bacteria Irradiated when packaged Exposed to radiation Food not radioactive Radiation passes through