Answer:
correct answer is option C (constant)
Explanation:
Radioactive decay of radioactive element occur at known rates, the unit of radioactive decay is called half-life. The amount of time a radioactive element takes for half of the parent atoms to decay is known as half-life of a radioactive element
During Radioactive decay radioactive elements emits a particle. It's impossible to predict exactly when a given atom of a substance will emit a particular particle, but the decay rate of a radioactive element over a long period of time is constant.
By radioactive decay scientist can determine the age of that particular element. If radioactive decay will vary than age cannot be determined from radioactive decay.
