All practice pages/Interatomic theory/Elements
Element 41, a transition metal
A metal that spent a century with two names, and the superconductor inside the magnets of MRI scanners and particle colliders.
Period 5, group 5. The other transition metals are tinted, and every cell opens its own article.
Niobium has 41 electrons, one for every proton, so the atom carries no charge. Below are the same 41 electrons written two ways.
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁴ 5s¹
Short form: [Kr] 4d⁴ 5s¹, where [Kr] stands for the 36 electrons krypton already has.
That list runs by shell. In the order the subshells fill it reads [Kr] 5s¹ 4d⁴, 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 3 here is 3s² 3p⁶ 3d¹⁰, and 2 + 6 + 10 is 18.
Niobium sits in period 5 and has 5 shells. The period number counts the shells.
The outer shell holds 1 electron. Those are the ones niobium can lose, gain or share, so they are the ones that decide what it bonds with.
Like other transition metals, niobium loses its outer s electrons, and often some d electrons as well, to form positive ions, and it can form more than one kind.
About 90% of the world's niobium comes from pyrochlore mined in Brazil, most of it from one mine at Araxá, and Canada produces most of the rest.
Charles Hatchett found it in 1801 in a mineral sent from Connecticut and called it columbium, after Columbia, a poetic name for America. Chemists confused it with tantalum until Heinrich Rose showed in 1844 that they were different and named it after Niobe, daughter of Tantalus. Niobium became the official name in 1949, though some metallurgists still say columbium.
Most goes into steel: a few hundredths of a percent make stronger, lighter steel for pipelines, car bodies and bridges. Niobium-titanium wire becomes a superconductor when cooled and fills the magnets of MRI scanners and the Large Hadron Collider. It also goes into jet engine alloys and brightly anodized jewelry.