The average time needed for half of the nuclei in a sample of a radioactive substance to undergo radioactive decay is called the "half-life." This period is a characteristic property of each radioactive isotope and varies significantly between different substances. During one half-life, the quantity of the radioactive material reduces to half of its original amount.
If I take a radioactive sample of 400 moles of an unknown substance and let it decay to the point of three half-lives I would have 50 moles left of the sample. 1/2 of what is left will decay in the next half-life. At the end of that half-life I will have 25 moles left of the unknown substance or 4/25.
After one half-life, half of the original radioactive atoms will decay, leaving 600 atoms. After a second half-life, another half of the remaining atoms will decay, leaving 300 atoms that have disintegrated out of the original 1200 atoms.
No, the length of time required for half of the radioactive atoms in a sample to decay is its half-life, not period. The half-life is the amount of time it takes for half of the radioactive atoms in a sample to undergo radioactive decay. Period typically refers to the time it takes for a complete cycle of a repeating event.
A geologist or archaeologist would use radiometric dating techniques to measure the ratio of unstable to stable atoms in a rock sample to estimate the age of the fossil it contains. This process involves analyzing the decay of radioactive isotopes present in the rock to determine its age.
Yes, and the question is ... ?
1/8 of the original amount remains.
After 5 half-lives, 3.125% (or 1/2^5) of a radioactive sample remains. Each half-life reduces the sample by half, so after 5 half-lives, there is only a small fraction of the original sample remaining.
After three half-lives, only 1/8 (or 12.5%) of the original radioactive sample remains. This is because each half-life reduces the amount of radioactive material by half, so after three half-lives, you would have (1/2) * (1/2) * (1/2) = 1/8 of the original sample remaining.
The length of time required for half of a sample of radioactive material to decay
The average time needed for half of the nuclei in a sample of a radioactive substance to undergo radioactive decay is called the "half-life." This period is a characteristic property of each radioactive isotope and varies significantly between different substances. During one half-life, the quantity of the radioactive material reduces to half of its original amount.
Measuring the activity of a radioactive isotope in a sample allows scientists to determine the amount of time that has passed since the sample was formed. By comparing the current activity of the isotope to its original activity, scientists can calculate the age of the sample, a technique commonly used in radiometric dating to estimate the age of rocks, fossils, and archaeological artifacts.
If I take a radioactive sample of 400 moles of an unknown substance and let it decay to the point of three half-lives I would have 50 moles left of the sample. 1/2 of what is left will decay in the next half-life. At the end of that half-life I will have 25 moles left of the unknown substance or 4/25.
For radioactive dating to be possible, the sample must contain a measurable amount of a radioactive isotope with a known decay rate. The sample must be isolated from sources of contamination that could affect the accuracy of the dating. Additionally, the sample must have remained a closed system since the radioactive isotopes were incorporated, in order to accurately measure the decay products.
The activity of a radioactive sample is calculated using the formula: Activity = λ*N, where λ is the decay constant of the isotope and N is the number of radioactive nuclei present in the sample. The unit of activity is becquerel (Bq).
After 2 half lives, 25% of the original radioactive sample remains unchanged. This is because half of the sample decays in each half life, so after 1 half life, 50% has decayed, and after 2 half lives, another 50% has decayed, leaving 25% unchanged.
It tells what fraction of a radioactive sample remains after a certain length of time.