B. The time needed for half of a sample of radioisotope to decay is the half-life of a radioisotope.
What is radioactive decay?
Radioactive decay is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive.
The most common types of decay are alpha decay, beta decay, and gamma decay, all of which involve emitting one or more particles.
The radioactive half-life means, the time required for half the atoms of a particular radioisotope to decay into another isotope.
The half-life of a radioactive isotope is the amount of time it takes for one-half of the radioactive isotope to decay.
The half-life of a specific radioactive isotope is constant; it is unaffected by conditions and is independent of the initial amount of that isotope.
Therefore,
The half-life of a radioisotope is the time needed for half of a sample of radioisotope to decay.
The correct option is B
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