What element has the symbol 'Fm'?

The story behind the answer

Fm is the symbol for Fermium, an actinide and synthetic, highly radioactive element with atomic number 100. The other options don’t match: Francium is Fr, Molybdenum is Mo, and “Fehlonium” isn’t a real element.

Fermium was discovered in 1952 in the debris of the first hydrogen bomb test (Ivy Mike), formed by multiple neutron captures in heavy elements. It’s named after Enrico Fermi, a pioneer of nuclear physics and reactor development. Memory tip: Fm = “Fermi-um”—think “FM radio tuned to Fermi.” Also remember the real symbols: Francium = Fr, Molybdenum = Mo.