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How much of radioactive substance remains after 15 hours if it's half life is 5 hours?
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∙ 8y ago
The half-life of a radioactive substance is the time that it takes for half of the atoms to decay. With a half-life of 10 days, half has decayed in this time. After 20 days, a further 10 days/another half life, a further half of the remainder has decayed, so 1/4 of the original material remains, 1/4 of 15g is 3.75 grams. This is the amount of original radioactive substance remaining, but it’s daughter isotope ( what the decay has produced ) is also present, so the original sample mass is effectively constant, especially in a sealed container. Even in an unsealed container, and assuming alpha ( helium nucleii) emission, a drop in mass per radioactive atom of 4 Atomic Mass units, compared with the original atom of, say 200 amu is only 2% mass decrease, less for heavier decaying nucleii.
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What does a half life fraction look like?
A half-life fraction is typically represented as a decimal or a percentage that indicates the fraction of a substance that remains after a certain amount of time has passed. For example, if a substance has a half-life of 2 hours and after 2 hours, only half of the original amount remains, the half-life fraction would be 0.5 or 50%.
If 20 of a radioactive substance disappears in 70 days what is its half life?
we need to know the units of 20. Is it grams, kilograms, %...
A sample of a radioactive substance decayed to 95 percent of its original amount after a year.what is the half life of the substance?
The half-life of a radioactive nuclide when 95% of it is left after one year is 13.5 years. AT = A0 2(-T/H) 0.95 = (1) 2(-1/H) ln2(0.95) = -1/H H = -1/ln2(0.95) H = 13.5
If radioactive radium has a half life of approximately 1599 years What percent of a given amount remains after 980 years?
Luckily got it on my last try it was apparently 65.39%
How many hours are in 7 and a half hours?
There are 7 full hours in 7 and a half hours.
How much of a radioactive substance remains after 5 hours if it's half-life is 5 hours?
6.25
How much of a radioactive substance remains after 10 hours if its half life is 5 hours?
After 10 hours, 25% of the radioactive substance remains because each half-life reduces the amount by half. So, after the first 5 hours, 50% remains, and after the next 5 hours, half of that amount remains, which is 25%.
If the half-life of a radioactive substance is 10 hours how long will it take for 50 percent of it to decay?
It would take 10 hours for 50 percent of the radioactive substance to decay because that is the definition of half-life. In this case, after 10 hours, half of the substance will have decayed, leaving 50 percent remaining.
What does not affect the half-life or a radioactive substance?
The temperature The total amount of the substance The addition of a catalyst ~
What is a half-life of radioactive substance if it takes 6 hours for 50 percent of it to decay?
6 hours. you have a hot one there!
What affect the half life of a radioactive substance A the mass of the substance B the temperature of the substance C the addition of a catalyst D the type?
A. The half-life of a radioactive substance is determined by the specific decay process of that substance, so it is not affected by the mass of the substance or the temperature. B. The mass of the substance does not affect the half-life of a radioactive substance. C. The addition of a catalyst does not affect the half-life of a radioactive substance. D. The type of radioactive substance directly determines its half-life, as different substances undergo radioactive decay at varying rates.
What is the half life of a radioactive substance if 2.4G decays to 1.80G in 66 hours?
The half-life of the radioactive substance is approximately 33 hours. This can be determined by observing that half of the initial amount decays in 33 hours, and the same applies to subsequent half-lives.
If the half life of a radioactive substance is 10 hours how long will it take for 75 percent of it to decay multiple choice question is it 15 hours 10 hours 5 hours or 20 hours?
It would take 10 hours for 75 percent of the radioactive substance to decay. This is because the half-life is 10 hours, so after one half-life 50 percent will decay, and after two half-lives 75 percent will decay.
Best definition of half-life for a radioactive substance?
The half-life of a radioactive substance is the time it takes for half of the atoms in a sample to decay. It is a constant characteristic of each radioactive isotope. After one half-life, half of the original substance will remain, and the other half will have decayed into other elements.
What does not affect the half life or a redioactive decay?
External factors such as temperature, pressure, and chemical reactions do not affect the half-life of a radioactive substance. The decay rate of a radioactive isotope remains constant over time regardless of these external conditions.
How much of a radioactive substance remains after 24 hours if its half life is 5 hours?
Using the formula Nt = N0*(1/2)t/t1/2 where Nt is the amount of stuff remaining after an amount of time, t, and t1/2 is the half-life, you get Nt = .036N0. So about 3.6% of the radioactive stuff is left.
What happens to the half life as the sample gets older?
The half-life remains constant for a particular radioactive substance, regardless of how old the sample is. This means that the rate at which the substance decays and the time it takes for half of it to decay remains consistent over time.
