What does the half life of an isotope allow scientist to determine?

A. The type of fossil

B. How much life is left in the animal

C. The age of the rock or fossil

D. The environment in which the fossil formed

C. the age of rock or fossil

Explanation:

Half life of a radioactive isotope tells us that how much time the isotope will take to decay to 50% of its original mass. Using the half life, the decay constant of the isotope can be calculated. Employing the decay rate, with the method known as radiometric dating, scientists calculate the age of rocks and fossil fuels. Age of earth is also approximated using the same technique.

Therefore, the option C is the correct answer.