The rate of decay for a radioactive sample
The half-life of the radioisotope Na-22 is 2.6 years.
It depends on the radioisotope. They do not all have the same half life.
The radioisotope with the shortest half-life among the following options is Polonium-214.
One-half of the original amount. That's precisely the definition of "half-life".
How long it takes for half of a sample to decay to another form.
16 hours.
The half-life of a radioisotope is the time it takes for half of the radioactive nuclei in a sample to decay. It is a characteristic property of each radioisotope and determines the rate at which the isotopes decay.
It is 432 years.
It is 7,380 years.
It is 15.02 hours.
It is 14.6 years.