anion
Meaning
A negatively charged ion, which is attracted to the anode (positive electrode) during electrolysis.
Structure
Usage
In a salt solution, chloride forms an anion that moves toward the positive electrode.
The anion exchange membrane allows only negatively charged ions to pass through.
The test confirmed the presence of a nitrate anion in the water sample.
Etymology
The word 'anion' was coined in 1834 by the English scientist Michael Faraday from Greek components to describe particles in motion during electrolysis. He derived it from the Greek neuter present participle 'ion' (going), based on the verb 'ienai' (to go). The prefix 'an-' (meaning "up" or, in this context, indicating movement toward the positive anode) was attached to specify the particle that travels toward the anode, contrasting with the 'cation' which travels toward the cathode. Thus, the term's literal construction, "that which goes up," logically evolved into the modern, specific scientific meaning of a negatively charged ion.
Analysis
an: Greek origin, a prefix meaning "not" or "without". ion: Greek origin, from 'ienai' meaning "to go". In scientific terminology, it refers to a particle that "goes" or moves during electrolysis.