A characteristic feature of radioactive isotopes is their unique half-life, representing the duration required for half of the isotope to decay. The table presents the half-lives of four isotopes.

Question

Using this data, which isotope would scientists avoid using for dating a fossil?

(1 point)
Responses

thorium-232
thorium-232

radon-222
radon-222

carbon-14
carbon-14

potassium-40
potassium-40

Answer 1

Scientists would avoid using radon-222 for dating a fossil.

This is primarily because radon-222 has a relatively short half-life of about 3.8 days, which makes it unsuitable for dating fossils that are typically thousands to millions of years old. In contrast, isotopes like carbon-14 and potassium-40 have longer half-lives, making them more appropriate for geological dating. Thorium-232 also has a long half-life, making it less practical for dating recent fossils compared to carbon-14.