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If a sample contains 100g of a radioactive isotope how much will be left after 3 half lives?
Wiki User
∙ 6y ago
There will be 125 grams of radium left. Keep it simple. Ih a half-life, half the sample decays. Half of 1000 grams is 500 grams, then half of 500 grams is 250 grams. Half of that again is 125 grams. And just so you know, the half-life of radium-226, the non-synthetic isotope of radium, is 1602 years. If this was the case here, 4806 years would have to pass to get the sample to decay as far as it did.
The remained quantity of radium after 3 x 1602 years is 125 grams.
Wiki User
∙ 14y ago
Wiki User
∙ 13y agoFor the element mass to become 1/4 of the original mass would take twice the half-life, or 2000 years.
The first 1000 years would reduce the example amount from 20 grams to 10, and the second 1000 years would reduce it again by half to 5 grams.
Wiki User
∙ 14y agoThink of a half-life as the time it takes for a certain amount of substance to only exist in half of that amount. For example, 1000 grams of element X will take 1 million years to become only 500 grams.
In another million years, element X's 500 grams will be reduced to 250 grams.
Finally, in 3 million years total, element X will be reduced from 250 grams to 125 grams.
Wiki User
∙ 12y agoIf the half-life is 1000 years, then 0.5 of the isotope will remain after 1000 years. Then 0.5 of the 0.5 will remain after another 1000 years, with the result that 0.25 will remain after 2000 years. The equation for half-life is ...
AT = A0 2(-T/H)
... where A0 is the starting activity, AT is the activity at time T, and H is the half-life in units of T.
Wiki User
∙ 14y agoafter 100 seconds there will be 2500 grams left from the substance. after 50 secs there will be 3750
Wiki User
∙ 13y agoAfter 3 half life cycles, there will be 12.5 mg left (50 mg after 1 half life, 25 mg after 2 half lifes, 12.5 mg after 3 half lifes).
Wiki User
∙ 14y agoOnly 125 grams after 4 806 years.
Wiki User
∙ 14y agoOnly 125 g after 4 806 years.
Steven Lopez
For apex: 2,000yrs
Wiki User
∙ 10y ago10g
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If the isotope have short half lives is that mean that the isotope is in a stable condition?
No. Only radioactive elements have half-lives, the half-life is the time that it will take for half of the atoms in a sample of a radioactive isotope to decay into another element or isotope. This is a constant property of the isotope and does not depend on the sample size. Stable isotopes never decay.
What is the difference between radioactive and non-radioactive isotope?
Radioactive minerals are unstable and emit radiation at a constant rate. They also have half lives and lose energy overtime. Nonradioactive minerals are stable, and by there own are incapable of emitting energy.
When does Parent and daughter isotopes occur?
The daughter isotope is the result of the radioactive disintegration of the parent isotope. For example radium is a product of the uranium disintegration.The two isotopes have different chemical (different atomic numbers, etc.), physical and nuclear properties.
A sample contains 1200 radioactive atoms of a particular nuclide After an interval of two half-lives how many atoms have disintegrated?
After two half life it must be 1200 x 1/2 x 1/2 = 300 atoms.
How do you shorten the half-life of a radioactive element?
Making any change in the half-life of an isotope of any element is generally something that lies outside our abilities. A very few radioactive materials have demonstrated a change in their half-lives when bathed in intense magnetic fields. Generally, however, the half-life on a given radionuclide is not something that can be changed. A number of experiments have been conducted wherein investigators have deliberately sought to influence radioactive half-life, but in all but the rarest cases, radionuclides are sublimely resistant to having their half-lives changed.
If the isotope have short half lives is that mean that the isotope is in a stable condition?
No. Only radioactive elements have half-lives, the half-life is the time that it will take for half of the atoms in a sample of a radioactive isotope to decay into another element or isotope. This is a constant property of the isotope and does not depend on the sample size. Stable isotopes never decay.
What is the amount of time it takes for three fourthsof a radioactive sample of an isotope of bromine to decay if the half life of the isotope is 16.5 hours?
It takes 2 half lives for an isotope to decay to 0.25 of its original value. If the half life is 16.5 hours, then 2 half lives is 33 hours. AT = A0 2(-T/H)
After three half-lives what percent of the radioactive isotope is remaining?
12.5% is remaining.
What is atomic life?
Strictly it is the half life of a particular isotope of the element. The half life of a radioactive isotope is the time taken for the number of radioactive atoms in the sample to decay to one half. Half lives vary hugely, from times like 10-21 seconds, to the very long, approaching the age of our solar system at 4.5x1012 years.
What percentage of a radioactive sample remains after 5 half-lives?
3.1 %
What is the difference between radioactive and non-radioactive isotope?
Radioactive minerals are unstable and emit radiation at a constant rate. They also have half lives and lose energy overtime. Nonradioactive minerals are stable, and by there own are incapable of emitting energy.
What is the half life of radioisotope?
Half life is the time taken for approximately half of the available nuclei in a sample of radioactive material to decay into something else. It's a characteristic of the isotope, for example, the half life of the isotope of iodine, I131 is 8.08 days. Half lives can vary from fractions of a second to thousands of years.
What is the half life of the radioactive isotope?
The half life is the period of time it takes radioactive decay to transmute one half of the isotope present at the start of the period to a different isotope, usually an isotope of a different element. This period of time is different for different isotopes, with known isotope half lives ranging from femtoseconds to many billions of years.
How many half-lives would have to elapse for a sample of a radioactive isotope to decrease from an activity of 96 cpm to an activity of 3 cpm?
It takes 5 half lives. The sample has been reduced to 3/96 or 1/32 of its original activity. This is 1/2 to the power of 5.
When does Parent and daughter isotopes occur?
The daughter isotope is the result of the radioactive disintegration of the parent isotope. For example radium is a product of the uranium disintegration.The two isotopes have different chemical (different atomic numbers, etc.), physical and nuclear properties.
After three half-lives what fraction of a radioactive sample will remain?
Approx 1/8 will remain.
Why After three half-lives what fraction of a radioactive sample remains?
The fraction that remains is 1/8.
