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.
Quick Answer. The formula for an oxide ion is O2-, which shows that it is an anion. An oxide is a compound formed by the combination of oxygen and another element. Oxygen can form many different oxide compounds with both metals and nonmetals.