All practice pages/Interatomic theory/Elements
Element 73, a transition metal
A metal that shrugs off almost every acid, found in the tiny capacitors of phones and laptops.
Period 6, group 5. The other transition metals are tinted, and every cell opens its own article.
Tantalum has 73 electrons, one for every proton, so the atom carries no charge. Below are the same 73 electrons written two ways.
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d³ 6s²
Short form: [Xe] 4f¹⁴ 5d³ 6s², where [Xe] stands for the 54 electrons xenon already has.
That list runs by shell. In the order the subshells fill it reads [Xe] 6s² 4f¹⁴ 5d³, 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.
Tantalum sits in period 6 and has 6 shells. The period number counts the shells.
The outer shell holds 2 electrons. Those are the ones tantalum can lose, gain or share, so they are the ones that decide what it bonds with.
Like other transition metals, tantalum loses its outer s electrons, and often some d electrons as well, to form positive ions, and it can form more than one kind.
Mined as tantalite, often mixed with niobium in the ore called coltan. Rwanda, the Democratic Republic of the Congo, Brazil and Nigeria produce most of it, and mining in conflict zones has made it a notorious conflict mineral.
Anders Gustaf Ekeberg found it in 1802 in minerals from Sweden and Finland. He named it after Tantalus of Greek myth, doomed to stand in water he could never drink, because its oxide sat in acid without taking any up. For decades chemists wrongly thought it was the same element as niobium.
Tantalum capacitors, small and reliable, fill phones, laptops, cars and medical devices. Its resistance to corrosion and to body fluids suits surgical implants and chemical plant equipment, and it goes into superalloys for jet engines and carbide cutting tools.