Element 107

Bohrium (Bh)

Transition metal · Period 7 · Group 7 · d-block

Bohrium (Bh) is element 107 of the periodic table, a transition metal in period 7, group 7 (d-block) with an atomic mass of 270 and is a solid at standard conditions.

At a glance

Atomic number
107
Symbol
Bh
Atomic mass
270 u
Category
Transition metals
Period
7
Group
7
Block
d-block
Phase at STP
solid

Electron structure

Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 5f14 6d5 7s2
Shorthand configuration
[Rn] 5f14 6d5 7s2
Electrons per shell
2, 8, 18, 32, 32, 13, 2
Oxidation states
+7

Physical properties

Bohrium has only ever been produced in quantities too small to weigh or observe in bulk. The physical and atomic values below are theoretical predictions from periodic trends and relativistic calculations, not measurements.

Density
37.1 g/cm³ (predicted)
Phase
solid

Atomic properties

Covalent radius
141 pm (predicted)
First ionization energy
740 kJ/mol (predicted)

Notable isotopes

Notable isotopes of Bohrium: mass number, atomic mass, natural abundance, and stability.
IsotopeMassAbundanceStability
Bh-270270.13336 - Half-life 61 seconds

Common uses

  • Scientific research only

Discovery

Year
1981
Discovered by
Peter Armbruster, Gottfried Münzenberg
Country
Germany

Frequently asked questions

Is bohrium a metal?
Yes. Bohrium is a metal, classified as a transition metal on the periodic table.
How many protons does bohrium have?
Bohrium has 107 protons. Its atomic number is 107, which is also the number of electrons in a neutral atom of bohrium.
What group and period is bohrium in?
Bohrium is in group 7 and period 7 of the periodic table, in the d-block.
What is the atomic mass of bohrium?
The atomic mass of bohrium is 270 u (unified atomic mass units).

Keep exploring

Bohrium's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.