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Sunday, June 19, 2016

Dubnium chemical element

Dubnium was discovered by researchers at the Nuclear Institute of Dubna and by American researchers from the University of California, Berkeley. 
The chemical symbol for Dubnium is Db and its atomic number is 105.
We find it listed in the periodic table of elements in group 5 and 7 period and block.
The Dubnium belongs to the family of transition metals such as for example the Silver, the Bohrium, cadmium, ...This element is Radioactive.
this element was named Dubnium after the city Dubna.


Dubnium chemical element


Atomic number (Z) 105
Group, block group 5, d-block
Period: period 7
Element category :transition metal
Standard atomic weight (Ar) [268]
Electron configuration: [Rn] 5f14 6d3 7s2 (predicted)[1]
per shell: 2, 8, 18, 32, 32, 11, 2 (predicted)

Physical properties
Phase: solid (predicted)
Density near r.t. : 29.3 g/cm3 (predicted)

Atomic properties
Oxidation states: 5, (4), (3) ​(parenthesized oxidation states are predictions)
Ionization energies: 1st: 664.8 kJ/mol
2nd: 1546.7 kJ/mol
3rd: 2378.4 kJ/mol (all estimated)
Atomic radius empirical: 139 pm (estimated)
Covalent radius: 149 pm (estimated)

Crystal structure :body-centered cubic (bcc) (predicted).
CAS Number: 53850-35-4