Dubnium (Db)

Unknown

Dubnium is a synthetic Transition whose chemistry reveals the limits of periodic law in superheavy elements, and with [Rn] 5f¹⁴ 6d³ 7s², dubnium (half-life 28 hours for Db-268) shows chemistry intermediate between niobium and tantalum. Its behavior is dominated by relativistic contraction of the 7s shell.

Key metrics

Density18g/cm³predicted

Melting point2,200Kpredicted

Boiling point5,500Kpredicted

Electronegativity1.3Paulingpredicted

Discovery

1967discovered

Discovered by: Joint Institute for Nuclear Research
Reactivity profile: Highly unstable radioactive metal
Reactivity: Medium
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[Rn]}\; \textcolor{#a855f7}{5_{f}^{14}}\; \textcolor{#22c55e}{6_{d}^{3}}\; \textcolor{#ef4444}{7_{s}^{2}}

[Rn] 5f14 6d3 7s2

Wave function

\Psi_{\text{Db}} \approx \frac{1}{\sqrt{105!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{105}(\mathbf{r}_{105}) \right|

Probability density $|\Psi|^2$ across the Db valence shell.

Crystal structure

Hexagonal Close-Packed

Lattice constantsa 1.00 · b 1.00 · c 1.63

Cell anglesα 90° · β 90° · γ 120°

Coordination number12

Atoms per cell2

Atomic packing factor0.74

Physical properties

Atomic radius: 149 pmpredicted
Ionization energy: 585 kJ/molpredicted
Electron affinity: 0 kJ/molpredicted
Crystal structure: Hexagonal close-packed (predicted)

Oxidation statespredicted

Acid/base

Basic

Strongly acidicStrongly basic

State at 25 °CSolid

2200 K5500 K298 K

predicted