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The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. Starting with 175 grams of a

radioactive isotope, how much will be left after 5 half-lives?
Use the calculator provided and round your answer to the nearest gram.
grams

1 Answer

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Final answer:

After 5 half-lives, there will be approximately 5.469 grams of the radioactive isotope remaining.

Step-by-step explanation:

The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. To find out how much will be left after 5 half-lives, we need to calculate the remaining mass after each half-life and then multiply it by 0.5 for each subsequent half-life.

Starting with 175 grams, after 1 half-life, half of the initial mass will remain: 175 * 0.5 = 87.5 grams.

After 2 half-lives, half of the mass remaining after the first half-life will remain: 87.5 * 0.5 = 43.75 grams.

Continuing this pattern, after 3 half-lives: 43.75 * 0.5 = 21.875 grams.

After 4 half-lives: 21.875 * 0.5 = 10.9375 grams.

Finally, after 5 half-lives: 10.9375 * 0.5 = 5.46875 grams.

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