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If 20 of a radioactive substance disappears in 70 days what is its half life?
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∙ 14y ago
we need to know the units of 20. Is it grams, kilograms, %...
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∙ 14y ago
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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.
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 many days in 9 and a half days?
9 and a half days = 9 and a half days , 228 hours, 13680 minutes, 820800 seconds.
Half an hour is how many days?
no days just half an hour
How many days in 4 in a half days?
In 4 and a half days, there would be 4 whole days and a half of the next day, 12 out of the 24 hours perhaps !
How do you determine the half life of a radioactive substance that has changed through radioactive decay After 40 days the original substance left is is one sixteenth of the original amount?
To determine the half-life of the substance, you can use the fact that after one half-life, the substance will be reduced to half of its original amount. In this case, after 40 days, the substance is reduced to one sixteenth of its original amount, which represents 4 half-lives (since 1/2^4 = 1/16). Thus, each half-life of this substance is 10 days.
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.
If 10 percent of a radioactive substance disintegrates in 4 days what is it's half-life?
The half-life of the radioactive substance is 13.8 days. This is calculated by dividing the natural logarithm of 2 by the decay constant, which is obtained from the percentage disintegration in a given time period. In this case, 0.1 (10 percent) disintegrates in 4 days.
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 is the time it takes for half of a raioactive substance to decay?
The time it takes for half of a radioactive substance to decay is known as the half-life of the substance. It is a fixed characteristic of a particular radioactive material and varies depending on the specific isotope.
30 gram of a radioactive substance that has a half-life of 2 days after 2 days how much will be left?
With radioactive decay, predicting when any individual atom will decay is nearly impossible. However, when a lot a particles are present, then it is possible to get a general idea of how much will decay in a certain period of time. The half-life is this measurement, and it is the time that it takes for one halfof the substance to decay. Hence half-life or how long it takes for half to "die".For any size sample of a substance, the half-life is how long it takes for half to be left, so for a substance with a half-life of 2 days, half of the substance will decay in two days. Therefore your answer is simply half of 30g which is 15g.Additional reading: http://simple.wikipedia.org/wiki/Radioactive_decay
What is the half life of a radioactive substance that has changed through radioactive decay after 40 days the original substance left is one sixteenth of the original amount?
The half-life of the radioactive substance is 10 days. This is because after every half-life, the amount of the substance reduces by half. Since one sixteenth is 2^4 (2 multiplied by itself 4 times), and 2^4 equals 16, it means 4 half-lives have passed (10 days x 4 = 40 days).
What is definition of half life?
The time required for half of the atoms in a radioactive substance to disintegrate.
A particle element has a half-life of 27 days after 54 days have elapsed how much of the radioactive material is left is called?
54 days is 2x27. After one cycle of a half life (27 days), one-half of the substance would be left. After a second cycle of a half life (27 more days, for a total of 54), one-half of one-half is left, or one-fourth.
The Time it takes for one half of the substance to decay into another substance?
This is known as the half-life of the substance. It represents the time it takes for the concentration of the original substance to reduce by half through decay. The half-life is a characteristic property of each radioactive substance.
What is radioactive half-life used for?
Radioactive half-life is used to measure the rate at which a radioactive substance decays. It is important in determining the amount of time it takes for half of a radioactive substance to decay into a stable form. This information is useful in various fields such as medicine, environmental science, and geology for dating purposes and evaluating risks associated with radioactive materials.
What does not affect the half-life or a radioactive substance?
The temperature The total amount of the substance The addition of a catalyst ~
