Definition
An atom or molecule that has gained one or more electrons, giving it a net negative electrical charge.
Plain English
A particle that has picked up extra electrons, so it now carries a small negative charge instead of being electrically balanced.
Context Anchor
Seen in basic electricity, static electricity, battery, and aircraft maintenance discussions involving electrical charge.
Derivation
From Latin negare, 'to deny or refuse,' and Greek ion, 'going' or 'a thing that moves.' Faraday coined 'ion' in the 1830s for charged particles that move through a solution toward an electrode. 'Negative' here simply marks which charge it carries.
Why Pilots Care
Understanding ions is the foundation for understanding how batteries, corrosion, and electrical circuits actually work — all of which a technician deals with daily.
Grounding Statement
A normal atom has equal protons and electrons and is neutral; add an extra electron and the atom now leans negative — that's a negative ion.
Intuition Check
Negative does not mean bad here. It means the particle has more negative electrical charge than positive electrical charge.
Example Sentence 1
When the battery discharges, negative ions move through the electrolyte toward the positive plate.
Example Sentence 2
Maintenance procedures included monitoring negative ion levels around the battery charging equipment to prevent corrosion.