Neither.
Argon is naturally occurring noble gas
Yes, there are synthetic isotopes of argon.
Bohrium is a synthetic radioactive element. It does not exist in nature.
Argon-40, the most common isotope is formed by the radioactive decay of potassium-40.
There are no radioactive isotopes of boron that are ordinarily found in nature. All elements have synthetic radioactive isotopes, however.
Carbon can certainly be found in nature, but some of its radioactive isotopes are synthetic.
Over 99.999% of argon is not radioactive. A trace of radioactive argon-39 can be found in nature, but it is not significant. Synthetic radioactive isotopes of argon exist, as they do for all elements.
Argon is a gas. It is not synthetic.
Radon is a noble gas and is radioactive. All of the other noble gasses have at least some synthetic radioactive isotopes. Radioactive isotopes of both krypton and argon exist in nature in trace quantities.
All transuranic elements are synthetic and radioactive.
no
Yes, there are synthetic isotopes of argon.
There are over twenty known isotopes of argon. Of these all but three are radioactive and decay. Of naturally occurring argon, very nearly 100% is not radioactive, with only traces of one radioactive isotope found.
Most argon is made by radioactive decay of potassium-40.
Most argon is made by radioactive decay of potassium-40.
All of the actinides are radioactive, and almost all are synthetic.
Synthetic elements are usually radioactive, but not necessarily so. It is conceivable for a non-radioactive neutral atom to be produced by a nuclear spallation reaction.
Yes, nobelium is an artificial element and radioactive.