Question

Carbon-14 has a half-life of 5,730 years. If the age of an object older than 50,000 years cannot be determined by radiocarbon dating, then


carbon-14 levels in a sample are undetectable after approximately ten half-lives.

carbon-14 levels in a sample are undetectable after approximately nine half-lives.

the half-life of carbon-14 is too long to accurately date the object.

a radioisotope with a shorter half-life should be used to date the object.

Answer 1

Care to help????

Answer 2

I think it should be:
a radioisotope with a shorter half-life should be used to date the object.
This is because every element has the identical isotope that just changes in neutrons, but has the same atomic number