non radioactive element
No, americium is an unstable and radioactive chemical element.
This is a radioactive chemical element.
A stable, nonradioactive atom must be formed.
Only the end product of the decay chain of uranium, a non radioactive isotope of lead.
If you had a stable element 115, then by definition there would need to be at least one non-radioactive isotope. Stable elements are those that have at least one nonradioactive isotope. Of course, the other isotopes of the element could all be radioactive.
You can use relative dating which is looking at the rocks around it, or you can use radiometric dating, which compares the amount of radioactive element with the amount of nonradioactive element in the rock.
A non-radioactive element is an element that has at least 1 isotope that is not radioactive. The means that at least one isotope has a stable nucleus that does not break down by shooting off high-energy particles.
Sodium Na 11 is a stable element.
All the three elements are generally non-radioactive.
Redioactive element
This phenomenon is not mandatory.
Bismuth (Bi) is the heaviest nonradioactive element but the next heaviest is Lead (Pb) and that is much more commonly used. The heaviest element that is naturally occurring, and also usable, though radioactive, is Uranium (U).