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aleksley [76]
3 years ago
9

The radioactive substance cesium-137 has a half-life of 30 years. The amount At (in grams) of a sample of cesium-137 remaining a

fter t years is given by the following exponential function.
At(t)=458(1/2)^(t/30)
Find the amount of the sample remaining after 20 years and after 50 years. Round your answers to the nearest gram as necessary.
Chemistry
1 answer:
stealth61 [152]3 years ago
6 0

<u>Answer:</u> The amount of sample left after 20 years is 288.522 g and after 50 years is 144.26 g

<u>Explanation:</u>

We are given a function that calculates the amount of sample remaining after 't' years, which is:

A_t(t)=458\times (\frac{1}{2})^{\frac{t}{30}

  • <u>For t = 20 years</u>

Putting values in above equation:

A_t(t)=458\times (\frac{1}{2})^{\frac{20}{30}

A_t(t)=288.522g

Hence, the amount of sample left after 20 years is 288.522 g

  • <u>For t = 50 years</u>

Putting values in above equation:

A_t(t)=458\times (\frac{1}{2})^{\frac{50}{30}

A_t(t)=144.26g

Hence, the amount of sample left after 50 years is 144.26 g

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