All practice pages/Interatomic theory/Elements
Element 25, a transition metal
Hidden in almost every steel, in the batteries in your remote, and in the cluster of atoms that lets plants split water.
Period 4, group 7. The other transition metals are tinted, and every cell opens its own article.
Manganese has 25 electrons, one for every proton, so the atom carries no charge. Below are the same 25 electrons written two ways.
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s²
Short form: [Ar] 3d⁵ 4s², where [Ar] stands for the 18 electrons argon already has.
That list runs by shell. In the order the subshells fill it reads [Ar] 4s² 3d⁵, 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 3d⁵, and 2 + 6 + 5 is 13.
Manganese sits in period 4 and has 4 shells. The period number counts the shells.
The outer shell holds 2 electrons. Those are the ones manganese can lose, gain or share, so they are the ones that decide what it bonds with.
Like other transition metals, manganese 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 0.1% of the crust, mined mostly as pyrolusite (MnO₂) in South Africa, Gabon and Australia. Fields of potato-sized manganese nodules cover large parts of the deep ocean floor.
Carl Wilhelm Scheele recognized in 1774 that the black mineral pyrolusite contained a new element, and his colleague Johan Gottlieb Gahn isolated the metal the same year. The name traces back to magnesia nigra, black magnesia, as pyrolusite was once called.
About 90% goes into steel: manganese removes oxygen and sulfur and makes the metal tougher, and high-manganese steel takes a beating in rail crossings, rock crushers and safes. It also goes into aluminum drink cans, and manganese dioxide is the cathode of ordinary alkaline batteries. Potassium permanganate disinfects and treats water.
Breathing manganese dust or fumes for years, as in some welding and mining work, can damage the nervous system.