Mendelevium - Md

Mendelevium (Md)

Mendelevium 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 number101
Representative isotope mass number[258]
Electron configuration[Rn] 5f13 7s2
Densitynot established
Melting point827 (estimated) °C
Boiling pointnot established

Mendelevium (element Md)

Uses and applications

Mendelevium is produced atom by atom and is used only for research. Its short-lived isotopes allow scientists to investigate the chemistry of elements near the end of the actinide series.

Mendelevium and water management

Mendelevium is not used in water treatment and is not expected in ordinary water supplies. Any occurrence in research or nuclear waste requires radionuclide-specific controls.

Occurrence and environmental context

Mendelevium 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

Mendelevium 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.

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Sources and further reading

Element page last reviewed: 24 October 2026 by Lenntech.