Carbon-14 is a radioactive element with a half-life of about 5,730 years. Carbon-14 is said to decay exponentially. The decay rate is 0.000121. We start with one gram of carbon-14. We are interested in the time (years) it takes to decay carbon-14. Find the amount (percent of one gram) of carbon-14 lasting less than 5,730 years. This means, find P(x > 5,730).

Element X decays radioactively with a half life of 9 minutes. If there are 170 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to decay to 26 grams?

A radioactive substance decays from 50 mg to 14 mg in 28 years according to the exponential decay model y = ae-bz, where a is the initial amount and y is the amount remaining after x years. Find the b -value. Round to the nearest hundredth, if needed. Use the EXACT b-value to write the exponential decay model for this substance with initial amount 50 mg. Use that model to find the half-life. Round to the nearest hundredth of a year, if needed. half-life years

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