Dubnium

Chaitra 26/06/2026 19:58:09 Updated 26/06/2026 19:58:09

Property	Value
Atomic Number	105
Element	Dubnium
Symbol	Db
Atomic Mass	[268] (most stable isotope)
Number of Neutrons	163 (Dubnium-268)
Number of Protons	105
Number of Electrons	105
Period	7
Group	5
Phase	Solid (predicted)
Radioactive	Yes
Natural	No (synthetic element)
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Transition Metal
Atomic Radius	— (not well established)
Electronegativity	— (not well established)
First Ionization Energy	~6.9 eV (estimated)
Density	~29 g/cm³ (estimated)
Melting Point	— (not well established)
Boiling Point	— (not well established)
Number of Isotopes	No stable isotopes (Db-268 most notable)
Discoverer	Joint Institute for Nuclear Research (Dubna) and Lawrence Berkeley National Laboratory
Year	1967
Specific Heat	— (not well established)
Number of Shells	7
Number of Valence Electrons	5