Let’s call the number of times this period of time has passed, n. So after 12 hours, n=2, after 24 hours n=4, etc. Let’s call the remaining amount of caffeine molecules in the body X. For each n, we divide C by 2. If n=3 then 18 hours have passed and we have halved our starting quantity of caffeine 3 times, or C/(2 3).
So if we think of a substance having 100 units originally and it has a half life of 2 hours. After two hours(one half life), 50 units will remain because 100(0.5)=50. So now, we have 50 units as our initial, so when another 2 hours passes (so a total of four hours) we have 25 units left because 50(0.5)=25. Finally, for the the last 2 hours (the
Which time frame correctly describes the range of half-lives? fractions of a second to billions of years. seconds to minutes. minutes to days. days to millions of years. fractions of a second to billions of years. Uranium-232 has a half-life of 68.9 years. A sample from 206.7 years ago contains 1.40 g of uranium-232.
Sodium-24 has a half-life of 15 hours. How many hours is three half-lives? Group of answer choices. 30 hours. 60 hours. 15 hours. 45 hours. 7.5 hours. Here’s the best way to solve it.
Approximately 90% of ketamine is excreted in the urine in the form of metabolites. 9 The half-life of ketamine, which is the time it takes for the total amount of drug in the body to be reduced by 50%, is about 2.5 hours in adults and 1 to 2 hours in children. 10. From a clinical standpoint it is estimated that a drug is effectively eliminated
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how many hours is half life 2
