Final answer:
The radioactive element named for an American chemist is americium (Am), a synthetic element used notably in smoke detectors and named after America.
Step-by-step explanation:
The radioactive element named for an American chemist is americium (f). Named after America, where it was first synthesized, americium is a synthetic element with the symbol Am and atomic number 95. Notably, americium-241 is an isotope used in smoke detectors.
Elements are often named after a place or a person, as in the cases of polonium, discovered by Marie Curie, named after her native country, Poland, or oganesson, named after the Russian physicist Yuri Oganessian. Similarly, element 115, Moscovium (Mc), is named after Moscow, and element 117, Tennessine (Ts), is named after Tennessee. The naming of elements is typically handled by IUPAC, the International Union of Pure and Applied Chemistry, and follows specific naming conventions.