The time it takes for half of a sample of an unstable isotope to decay to a stable form is called theGroup of answer choicesdemidose.half-life.semichron.half-morph.

Measurements of a certain isotope tell you that the decay rate decreases from 9354 decays/minute to 3185 decays/minute over a period of 3.00 days. The half-life of this isotope in units of days and to one decimal place is:

Select the statement that is falseGroup of answer choicesActivity is proportional to the number of nuclei in the sampleThe rate of decay depends on the number of nuclei presentC-14 dating is appropriate for objects up to one million years oldA high activity corresponds to a short half-life

The half-life of a radioactive substance is best define as:Group of answer choicesThe time it takes for half of the substance to regenerateThe time it takes for a given amount to increase by halfThe time it takes for a given amount to reduce by halfThe time it takes for half the substance to react

radioactive isotope decays with a rate proportional to the original amountof material present. If originally there is 50mg of the material present and aftertwo hours it has lost 10% of its mass, determine the half-life, the time at which itis half its original mass.

What is the half-life of a radioisotope?A.The amount of time it takes for a radioisotope to get halfway to a stable formB.The amount of time a radioisotope exists as the parent elementC.The amount of time it takes for half of the radioisotope to formD.The amount of time it takes for half of the material to decay