What are these isotopes...?

Question

I was helping my mom compose questions for her physical science class using a pdf chart listing several unstable isotopes and information about their decay. After we finished, we saved the questions and failed to save the chart. We now have questions but the isotopes that are the correct answers are unknown. Could someone identify the isotopes by just their half-lives?

Here are the half-lives:
5 years
12 hours
27 min
20 min

Answer 1

Well...not really. If you provided each isotopes decay constantg then yeah.

t_1/2 = 0.693/(decay constant)