17,200 Years
It tells what fraction of a radioactive sample remains after a certain length of 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.
The fraction that remains is 1/8.
Iodine-131 has a half-life of about 8 days.
the half-life
The sample must contain radioactive elements.
Carbon-14 dating is the measurement of an object's age by comparing the amount of carbon-14 to the amount of carbon-12 and carbon-13 present in the sample.
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.
It will take practically forever. Carbon-12 is not radioactive.
No and yes. It depends on the way you define activity. Carbon-14 undergoes radioactive beta decay. The activity of Carbon-14 is given in terms of disintegrations per minute per gram of carbon. So, if you have a 100 gram sample and a 1 gram sample, there will be 100 times more disintegrations per minute with the larger sample. But typically, we are more interested in the time it takes a certain percentage to decay. Time values like half life will be the same for large and small samples.
The length of time required for half of a sample of radioactive material to decay
It tells what fraction of a radioactive sample remains after a certain length of time.
Not sure what you mean by "had-lives". After 3 half lives, approx 1/8 would remain.
Yes, and the question is ... ?
Carbon-14 is radioactive, with a half-life of 5730 years. Archaeologists use the amount of carbon-14 left in a organic sample to determine the age of the sample. This is known as radiocarbon dating.
i got no idea
An eighth remains.