Question

How can a scientist assess whether a pure niobium (Nb) sample is responsible for contaminating the lab with radioactivity?

Answer 1

Test the niobium sample to see whether it now contains other elements.
The 2nd choice doesn't work because niobium oxides aren't radioactive (unless the niobium itself was radioactive, but you can't tell with this method).
The last 2 choices don't work because temperature and pressure don't affect the rate of decay.

Answer 2

Its A lol

A

A

A

A Just put A