Question

all the elements beyond ______ are manmade and and radioactive

Answer 1

All elements with atomic numbers greater than 83 are radioisotopes meaning that these elements have unstable nuclei and are radioactive. All of the elements found on the periodic table above Uranium, element 92, are man-made.

Answer is 92.

Answer 2

Anything with an atomic number greater than 92(uranium) is called transuranic,i.e they are man made and radio active.
Eg: Np,Am,Pu