Fermium - Fm

Fermium (Fm)

Fermium is a radioactive actinide produced in very small quantities. It does not have a standard atomic weight; the bracketed value below identifies a representative isotope mass number.

Atomic number100
Representative isotope mass number[257]
Electron configuration[Rn] 5f12 7s2
Densitynot established
Melting point1527 °C
Boiling pointnot established

Fermium (element Fm)

Uses and applications

Fermium has no applications outside scientific research. It is made in extremely small quantities and studied to understand heavy-element chemistry and nuclear properties.

Fermium and water management

Fermium is not a water-treatment chemical. If present in nuclear or research waste, its isotope and activity must be identified and the material managed as radioactive waste under applicable controls.

Occurrence and environmental context

Fermium is a synthetic actinide with no stable isotopes. Its occurrence outside controlled production is extremely limited. Environmental assessment, if relevant, depends on isotope, activity, chemical form, and the specific source.

Health and safety

Fermium requires specialised radiological controls. Exposure risk depends on isotope, activity, chemical form, and exposure route. Follow applicable radiation-protection procedures and institutional requirements when handling radioactive materials or waste.

Back to the periodic table of elements

Sources and further reading

Element page last reviewed: 24 October 2026 by Lenntech.