Question

A fossil is 3 half-life old. Measured Uranium-235 has half-life of 704 million years. How many years old is this fossil?

Answer 1

Answer: Uranium is not a problem in this case, as its radioactivity is very low. This is due to the long half-life. How much uranium will decay per second with a half-life of 700 million years? This is a very insignificant figure.