The half-life of a certain tranquilizer in the bloodstream is 23 hours. How long will it take for the drug to decay to 85% of the original dosage? Use the exponential decay model, A = Apekt, to solve. hours (Round to one decimal place as needed.)

The half-life of radioactive actinium ( 227AC ) is 21.77 years. What percent of a present amount of radioactive actinium will remain after 19 years?

The half-life of a radioactive material is about 34.2 years. How much of the material is left after 20 years?

A radiation safety officer is working with 112 grams of a radioactive substance. After 17 days, thesample has decayed to 80 grams. Rounding to fivesignificant digits, write an exponential equationrepresenting this situation. To the nearest day, whatis the half-life of this substance?