If an Isotope Has a Half-Life of 4 Million Years

Multiple Choice

If an isotope has a half-life of 4 million years and a fossil is 16 million years old, how much of the original isotope will be found in the fossil?

A) one-half of the original amount
B) one-quarter of the original amount
C) one-eighth of the original amount
D) one-sixteenth of the original amount