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How much of radioactive substance remains after 15 hours if it's half life is 5 hours?
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 may or may not be a fraction. The half life of carbon 14, for example, is 5715 years - not really a fraction, unless you are thinking in terms time periods which are much longer than a year.
How much Cu-61 (half-life about 3 hours) would remain from a 2 mg sample after 6 hours?
The half-life of Cu-61 is approximately 3 hours, meaning after each half-life, half of the remaining substance decays. After 6 hours, which is two half-lives, the amount remaining can be calculated as follows: starting with 2 mg, after the first 3 hours (one half-life), 1 mg remains, and after the next 3 hours (the second half-life), 0.5 mg remains. Therefore, after 6 hours, 0.5 mg of Cu-61 would remain from the original 2 mg sample.
Does the size of a radioactive sample affect half-life?
No, the size of a radioactive sample does not affect its half-life. The half-life is a characteristic property of a radioactive isotope, defined as the time it takes for half of the radioactive atoms in a sample to decay. This property is intrinsic to the isotope itself and remains constant regardless of the amount of material present. Thus, whether you have a small or large sample, the half-life will remain the same.
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
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?
The half-life of a radioactive isotope is defined as the time taken for the isotope to decay to half of its initial mass. So to decay to 50 percent of its initial mass will take one half-life of the isotope. One half-life of the isotope is 10 hours so the time taken to decay is also 10 hours.
If a specimen of a given radioactive substance is reduced in size its half life?
The half-life of a radioactive substance is an intrinsic property that does not change regardless of the size of the specimen. Whether the sample is large or small, the time it takes for half of the radioactive atoms to decay remains constant. Therefore, reducing the size of the specimen does not affect its half-life.
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 a radioactive substance that decays from 2.4g to 1.8g in 66 hours is 159 hours. AT = A0 2(-T/H) 1.8 = (2.4) 2(-66/H) 0.75 = 2(-66/H) log2(0.75) = log2(2(-66/H)) -0.415 = -66/H H = 159
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.
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?
Its 5 hours. 50% of the substance is decayed at 10 hours (that is what half life means. It's full life is 20 hours). Multiple 75% times 20 hours to find that 75% is 15 hours. Subtracrt 15 hours from 20 hours to get the answer of 5 hours for the decay of 75% of the substance.
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.
