Commutator (electric) A commutator is a moving part of a rotary electrical switch in certain types of electric motors and electrical generators that periodically reverses the current direction between the rotor and the external circuit. It consists of a cylinder composed of multiple metal contact segments on the rotating armature of the machine.
The word equation that would represent the formation of lithium oxide from lithium metal and oxygen is: lithium + oxygen to lithium oxide. In chemical symbols, the balanced chemical equation is expressed as: Li + O2 = Li2O.
The alkali metals and alkaline earth metals form three different types of binary oxygen compounds: (1) oxides, containing oxide ions, O 2â, (2) peroxides, containing peroxide ions, O 2 2â, which contain oxygen-oxygen covalent single bonds, and (3) superoxides, containing superoxide ions, O 2 â, which also have oxygen-oxygen covalent bonds but with one fewer negative charge than peroxide ions.