where on the periodic table are most natural radioactive nuclides located?

Answer 1

I really don't know how to answer this question because H, the fist element in the periodic table, has a radioactive isotope. Also, carbon, near the beginning, and Po, Ra, U, and a host of others at the end of the table are radioactive naturally. There are some naturally occurring radioactive isotopes in the middle of the table. Perhaps you need to rephrase the question.