Dubnium - Db

Chemical properties of dubnium

Dubnium (Db) is a synthetic, radioactive element with atomic number 105. It is assigned to Group 5, below niobium and tantalum. Dubnium has no stable isotopes; the bracketed mass number [268] identifies a radioactive isotope rather than a standard atomic weight. Only a few atoms have ever been made, so bulk physical properties such as density and melting point are unknown.

Research and occurrence

Dubnium does not occur naturally. It is produced in nuclear-reaction experiments and studied in specialised chemistry research. No commercial, environmental, or water-treatment application is known.

Health and environmental context

Dubnium is radioactive and exists only as short-lived atoms in controlled research settings. It is not an element encountered in ordinary environmental or process-water treatment.

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Dubnium page last reviewed: 24 October 2026 by Lenntech.