All practice pages/Interatomic theory/Elements
Element 107, a transition metal
Named after Niels Bohr, whose model of the atom arranged electrons in shells.
Period 7, group 7. The other transition metals are tinted, and every cell opens its own article.
Bohrium has 107 electrons, one for every proton, so the atom carries no charge. Below are the same 107 electrons written two ways.
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹⁴ 6s² 6p⁶ 6d⁵ 7s²
Short form: [Rn] 5f¹⁴ 6d⁵ 7s², where [Rn] stands for the 86 electrons radon already has.
That list runs by shell. In the order the subshells fill it reads [Rn] 7s² 5f¹⁴ 6d⁵, because a subshell fills by its energy, not by its shell number.
The simple form counts electrons shell by shell. The orbital form says which subshell each one sits in: s holds 2, p holds 6, d holds 10 and f holds 14. Shell 4 here is 4s² 4p⁶ 4d¹⁰ 4f¹⁴, and 2 + 6 + 10 + 14 is 32.
Bohrium sits in period 7 and has 7 shells. The period number counts the shells.
No one has measured this configuration. Only a few atoms of bohrium have ever existed, so it is predicted from the pattern of the table.
The outer shell holds 2 electrons. Those are the ones bohrium can lose, gain or share, so they are the ones that decide what it bonds with.
Only a handful of atoms have ever been made, each lasting seconds or less, so its chemistry is predicted from its place in the table rather than measured.
Not found in nature. It is made a few atoms at a time in particle accelerators by fusing lighter nuclei, and each atom decays within seconds to hours.
Peter Armbruster and Gottfried Münzenberg's team at the GSI laboratory in Darmstadt, Germany, made it in 1981 by fusing chromium and bismuth nuclei. It was named after the Danish physicist Niels Bohr.
Research only. Experiments with a handful of atoms showed it forms an oxychloride, as rhenium above it does.