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What is the half-life of 20 g of a radioactive sample if 5 g remain after 8 minutes?
Wiki User
∙ 7y ago
If it was fully radio-active at the beginning, after 5 hrs it is 50%, at 10 hrs it is 25%, at 15 hrs it is 12.5%, and at 20 hrs it is only 6.25% as radioactive as it was at the beginning.
Wiki User
∙ 15y ago
Wiki User
∙ 7y ago5g is 1/4 of the starting amount. which means it got halved twice. which means half life is 4 minutes..
20g after 4 mins becomes 10g and again after four more this 10g becomes 5g
anon
4 min 1/2 life
Wiki User
∙ 14y ago6.25%
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What is the time needed for half of a sample of a radioactive isotope to break down to form daughter isotopes called?
halflife
How does the length of the half-life of the element correspond to the radioactivity of the element?
The length of time required for half of a sample of radioactive material to decay
What is the half-life of a radioactive sample of bromine-74 in 25 minutes in a 4mg sample?
The question does not make sense. The half-life of bromine-74 is, in fact, 25.4 minutes. In 25 minutes, that 4mg sample will decay to 2mg. In 25 more minutes it will decay to 1mg. In 25 more minutes it will be 0.5mg. And so on and so forth. If you meant to ask how much will remain after a given period of time, please restate the question.
How much cesium would remain from a 10g sample after 4 years?
I suppose that you think to the radioactive isotope Cs-17; After 4 years remain 9,122 g.
What fraction of the radioactive atoms currently present will be left after four minutes if a sample of gas has a half life of two minutes?
200
What is the time needed for half of a sample of a radioactive isotope to break down to form daughter isotopes called?
halflife
After three half-lives what fraction of a radioactive sample will remain?
Approx 1/8 will remain.
How does the length of the half-life of the element correspond to the radioactivity of the element?
The length of time required for half of a sample of radioactive material to decay
What is the half-life of a radioactive sample of bromine-74 in 25 minutes in a 4mg sample?
The question does not make sense. The half-life of bromine-74 is, in fact, 25.4 minutes. In 25 minutes, that 4mg sample will decay to 2mg. In 25 more minutes it will decay to 1mg. In 25 more minutes it will be 0.5mg. And so on and so forth. If you meant to ask how much will remain after a given period of time, please restate the question.
How much of an 800-gram sample of potassium-40 will remain after 3.9109 years of radioactive decay?
100 grams
How much cesium would remain from a 10g sample after 4 years?
I suppose that you think to the radioactive isotope Cs-17; After 4 years remain 9,122 g.
What fraction of the radioactive atoms currently present will be left after four minutes if a sample of gas has a half life of two minutes?
200
How much of an 800-gram sample of potassium-40 will remain after 3.9 X 109 years of radioactive decay?
100 grams
What happens to a radioactive material over time?
It disintegrates into its daughter nuclei that are much more stabler than the radioactive nuclei. If a sample of radioacictive material is left it will decay into another element over a period of time. Note that complete decay is not possible. A fraction of the original radioactive material will always remain in the sample.
How long will it take half of a radioactive sample to decay?
The length of time depends on the element and isotope, but the point at which half of the sample has decayed is known as the half-life.
What must be true for radioactive dating to be possible with a certain sample?
The sample must contain radioactive elements.
The half-life of actinium 227 is 21.772 years After 50 years how much of a 1500 g sample will remain radioactive?
Approx. 313 grams
