Our Elements
Menu

Dubnium

Element 105 · Transition metal

Specimen

Atomic number
105
Atomic mass
[268]
State at room temperature
Solid
Melting point
Unknown
Boiling point
Unknown
Density
Unknown
Discovered
1967

Mass number of the longest-lived isotope, from IUPAC.1 Other physical data from PubChem.2

Can I eat it?

In food and water
Never made in amounts you could eat. Only a handful of dubnium atoms have ever been made. There is not enough of it to weigh. 3

See every element.

The atom

Db
ShellElectrons
1 (K) 2
2 (L) 8
3 (M) 18
4 (N) 32
5 (O) 32
6 (P) 11
7 (Q) outermost 2
Total105

Configuration [Rn] 5f¹⁴ 6d³ 7s²

5f ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓
6d ↑ ↑ ↑
7s ↑ ↓
A shell diagram: each ring is an electron shell and each dot is one electron. The nucleus holds 105 protons. The outermost shell is shown in red. Electrons do not travel on rings: they fill orbitals, regions where an electron is likely to be found. The boxes are those orbitals for the electrons outside the Rn core, with one arrow per electron. This configuration is a prediction; it has not been measured.

Related elements

Group 5
V Vanadium Nb Niobium Ta Tantalum

New elements by e-mail

Sources

  1. 1

    IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW), 2024. Radioactive Elements .

    Mass number and half-life of the longest-lived isotope of the 34 elements with no standard atomic weight.

  2. 2

    National Center for Biotechnology Information (PubChem), 2026. Periodic Table of Elements .

    Electron configuration, melting and boiling points, density and discovery year for all 118 elements.

  3. 3

    Los Alamos National Laboratory, Periodic Table of Elements, 2026. Dubnium .

    • Even its atomic mass is unknown—there isn't enough of the element to weigh. ... With just a handful of atoms ever created, studies on dubnium have only been conducted on individual atoms.