105Db

Dubnium

Transition metalunknownblock d

A superheavy element at the centre of the Cold War naming war, called hahnium and nielsbohrium in turn before Dubna's own name won out.

Atomic number	105
Mass number (longest-lived isotope)	268 g/mol
This element has no stable isotope, so it has no standard atomic weight. The figure above is the mass number of its longest-lived isotope — a convention, not a measurement of a natural mixture.
Group · period	5 · 7
Electron configuration	[Rn] 5f¹⁴ 6d³ 7s²

About Dubnium

Element 105 was claimed by both Dubna and Berkeley in 1970, and for two decades American papers called it hahnium while Soviet papers called it nielsbohrium; IUPAC at one point proposed joliotium, and a 1994 draft gave the name dubnium to element 104 instead. The 1997 settlement gave 105 to Dubna as compensation for awarding 104 and 106 to Berkeley, and the name dubnium honours the Joint Institute for Nuclear Research town rather than a person — the only element named for a laboratory's home town. Chemically it behaves as group 5 should, forming volatile oxychlorides like niobium and tantalum, though with a marked relativistic preference for fluoride complexes that its lighter homologues do not share.

Use 268 g/mol in these solvers

Moles from Mass (n = m/M)

n = \frac{m}{M}

Opens with M = 268 g/mol already filled in

Gas Density from Molar Mass

\rho = \frac{PM}{RT}

Opens with M = 268 g/mol already filled in

Faraday's Law of Electrolysis (m = QM/nF)

m = \frac{Q M}{n F}

Opens with M = 268 g/mol already filled in

Ion Concentration as CaCO₃ Equivalent

C_{\mathrm{CaCO_3}} = C_{\mathrm{ion}} \times \frac{50.04}{\mathrm{EW}}

Opens with EW = 268 g/mol already filled in

Acid Feed to Reduce Alkalinity

\dot m = \frac{\Delta \mathrm{Alk} \, Q \times \frac{\mathrm{EW}}{50.04}}{p/100\%}

Opens with EW = 268 g/mol already filled in

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