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If half lives is 1 and time elasped is 1620 year what is mass remaining?
Wiki User
∙ 9y ago
Half life has unit. That is unit of time. So it has to be mentioned. Let us assume that half life is 1 year. Okay. Now to know about the mass remaining we have to get the ratio (1/2)^1620. Hence remaining will be 1/(2^1620) * mass at the beginning
Wiki User
∙ 9y ago
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What fraction of a radioisotope is remaining if it undergoes six half-lives?
1 / 26 = 1 / 64.
In a time equal to two half-lives of a radioactive isotope would you expect all of that isotope to have decayed?
No. In two half-lives, a radioactive isotope will decay to one quarter of its original mass. In one half-life, one half of the mass decays. In the next half-life, one half of the remaining mass decays, and so on and so forth. At each half-life point, you would see 0.5, 0.25, 0.125, 0.0625, etc. remaining. The logarithmic equation is... AT = A0 2(-T/H)
How many milligrams of a 15.0 mg sample of radium-226 remain after 6396 years if the half-life of radium-226 is 1599?
One sixteenth of a gram. 1st halflife- 1/2 gram 2nd, 1/4 3rd 1/8th 4th halflife, 1/16th
What is the half-life of Tb?
The Terbium isotope found in nature (159Tb) is stable. Like all elements, Terbium has radioisotopes, of which 33 have been created to date. 158Tb is the most stable of these, with a half-life of 180 years, 157Tb has a 71 year half-life. 160Tb has a half-life of 72.3 days. Most of the remaining radioisotopes have half-lives that are less measured in seconds, although some have half lives that are measured in days.
If an isotope has a half-life of 300 years after what length of time will three quarters of a sample decay?
After 300 years: 50% gone, 50% remaining. After another 300 years: half of the 50% remaining is gone = 25% of the original sample. 25% of the original remains. So, after 600 years, 3/4 is gone, 1/4 remains.
After three half-lives what percent of the radioactive isotope is remaining?
12.5% is remaining.
How much hydrogen-3 will remain after 60 years if the original sample have a mass 80.0 g and a the half-life of hydrogen-3 is 12 years?
Fraction remaining = 0.5^n where n = # of half lives that have elapsed60 yrs x 1 half life/12 yrs = 5 half lives have elapsed Fraction remaining = 0.5^5 = 0.03125 mass remaining = 0.03125 x 80.0 g = 2.5 g remaining
What fraction of iodine 131 is remaining after 4 half- lives?
1/24 = 1/16
What fraction of a radioisotope is remaining if it undergoes six half-lives?
1 / 26 = 1 / 64.
How many half-lives have passed if 12.5 of a radioactive sample are left?
3 At the end of the first half life, there will theoretically be 50% remaining. 2 half lives: 25% 3 half lives:12.5 %
After 6 half-lives What percentage of a radioactive sample remain?
After 6 half lives, the remaining will be (1/2)6 i.e 1/64 th of the initial amount. Hence by percentage it would be 1.5625 %
How long will it take for a 12.0-g sample of iodine-131 to decay to leave a total of 1.50 g of the isotope The half-life of iodine-131 is 8.07 days?
half life is 8.1 days, so it takes 8.1 days for half the iodine sample to decay. It takes another 8.1 days for half of the remaining sample (ie. 1/4th of the original sample) to decay. So it takes 16.2 days for 3/4th of the sample to decay.
In a time equal to two half-lives of a radioactive isotope would you expect all of that isotope to have decayed?
No. In two half-lives, a radioactive isotope will decay to one quarter of its original mass. In one half-life, one half of the mass decays. In the next half-life, one half of the remaining mass decays, and so on and so forth. At each half-life point, you would see 0.5, 0.25, 0.125, 0.0625, etc. remaining. The logarithmic equation is... AT = A0 2(-T/H)
How many milligrams of a 15.0 mg sample of radium-226 remain after 6396 years if the half-life of radium-226 is 1599?
One sixteenth of a gram. 1st halflife- 1/2 gram 2nd, 1/4 3rd 1/8th 4th halflife, 1/16th
Why is it called half-life of an atom?
The half-life of an atom is how long it takes for half of the atom's mass to radioactively decay. This occurs exponentially; therefore, after 2 of the atom's half-lives have passed, 3/4 of the atom will have decay (half during the first half-life, then half of the remaining mass, or one quarter, during the second).
What is the half-life of Tb?
The Terbium isotope found in nature (159Tb) is stable. Like all elements, Terbium has radioisotopes, of which 33 have been created to date. 158Tb is the most stable of these, with a half-life of 180 years, 157Tb has a 71 year half-life. 160Tb has a half-life of 72.3 days. Most of the remaining radioisotopes have half-lives that are less measured in seconds, although some have half lives that are measured in days.
How much Cu-61 (half-life about 3 hours) would remain from 2 mg sample after 6 hours?
6 hours = 2 half lives, thus 25 % would remain. 0.25 x 2 mg = 0.5 mg.Done another way...fraction remaining = 0.5^n where n = number of half lives = 6hr/3hr = 2fraction remaining = 0.5^2 = 0.250.25 x 2 mg = 0.5 mg
