Question

At the beginning of an experiment, a scientist has 108 grams of radioactive goo. After 240 minutes, her sample has decayed to 3.375 grams. What is the half-life of the goo in minutes? Preview How many grams of goo will remain after 99 minutes? Preview How many grams of goo will remain after 218 minutes? Preview Round your answers to the nearest tenth as needed. Get help: Video Drintendent

Answer 1

formula Alt) = Ao ert given, Initial amount (A) = 108 grams Remaining amount (A) = 3.375 grams Time (t = 240 minutes Solh subtitute given values into equ o 3.375 108 et(240) e81240) 3.375 108 {ilme=2 in (0.03125) = 7(240) Inies inlo.03125) 240 7 r=-0.0144456 Hence, the function is Altha 1082-10-0144456) t Half lifet a to find the half life 54 =108 ē (0.01944561€ plug Alt):54 Ź =ē.0144256 37 t = im (2) -0.01956 tn 48 . Half life is 148 minutes An

Remaining amount after qq minutes et=99) A(99) : 108 € -(0.0144456)799) A199) = 25.83 a fter 99 minutes is The remaing amount 115.4 gram) or 132.goomne Remaining amount after 218 minutes A1218) = 108 e-(0.0144456)(218) Al218 ) =4.6 The remaining amount after 218 minutes is 4.6 6 gra rams Am.
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