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A 60-g sample of radioactive isotope is measured after two half-lives have passed. What pair of percentages describes the sample after two half-lives?.

User Dskinner
by
3.9k points

2 Answers

6 votes

Answer:

b. 25% unchanged and 75% stable

Step-by-step explanation:

got it right on edge

User Jon Skarpeteig
by
4.0k points
10 votes

Answer:

25% is left 15 gm

Step-by-step explanation:

(1/2)^2 = 25%

User Arthur Ronconi
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4.8k points