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The 1/2 life of po-218 is 3 minutes. if you start with 20.0 grams, how long will it be before only 1.0 grams remains

User Derekhh
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Final answer:

The half-life of Po-218 is 3 minutes. It will take 18 minutes for only 1.0 gram of Po-218 to remain.

Step-by-step explanation:

The half-life of a radioactive isotope is the time it takes for half of the sample to decay. In this case, the half-life of Po-218 is 3 minutes.

To determine how long it will take for 1.0 gram of Po-218 to remain, we can use the concept of half-life. We start with 20.0 grams, and at each half-life, the amount of Po-218 is halved. Therefore, we need to find the number of half-lives it takes for the amount to reduce from 20.0 grams to 1.0 gram.

Each half-life is 3 minutes, so we divide the total time by 3 to find the number of half-lives. If it takes 3 minutes for one half-life, it will take 3 x (number of half-lives) minutes for the amount to reduce to 1.0 gram. So, we have:

20.0 grams / 2 = 10.0 grams (1 half-life)

10.0 grams / 2 = 5.0 grams (2 half-lives)

5.0 grams / 2 = 2.5 grams (3 half-lives)

2.5 grams / 2 = 1.25 grams (4 half-lives)

1.25 grams / 2 = 0.625 grams (5 half-lives)

0.625 grams / 2 = 0.3125 grams (6 half-lives)

So, it will take 6 x 3 = 18 minutes for only 1.0 gram of Po-218 to remain.

User Mizzle
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