There are 28 man-made elements on the periodic table, of which 8 may exist as trace elements in natural state
technetium (Tc), 43
promethium (Pm), 61
neptunium (Np), 93
plutonium (Pu), 94
americium (Am), 95
curium (Cm), 96
berkelium (Bk), 97
californium (Cf), 98
einsteinium...