Answer:
Element not or no longer occurring on earth, but artificially generated by nuclear reaction.
Explanation:
A synthetic element is one of 24 chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor or particle accelerator, or detonation of an atomic bomb; and thus are called "synthetic", "artificial", or "man-made". The synthetic elements are those with atomic numbers 95–118.
