Definition
An atom that has lost one or more electrons, leaving it with a net positive electrical charge. Because protons in the nucleus now outnumber the surrounding electrons, the atom carries a positive charge equal to the number of electrons lost.
Plain English
An atom that has given up one or more of its electrons, so it ends up with more positive than negative charge.
Context Anchor
Seen in basic aircraft electrical theory, static electricity, and battery discussions in maintenance training.
Derivation
From Greek 'ion' meaning 'going' — chosen because ions move toward electrical charges. 'Positive' here simply marks the direction of charge: it has more protons (positive) than electrons (negative).
Why Pilots Care
Understanding positive and negative ions is the foundation for understanding electrical current, battery chemistry, and corrosion — all of which a technician deals with directly when servicing aircraft systems.
Analogy
Think of a balanced scale with equal negative and positive weights. If you remove some negative weight, the scale is no longer balanced and the positive side is heavier.
Grounding Statement
If you pull an electron away from a neutral atom, what's left behind is a positive ion.
Intuition Check
Positive does not mean “good” or “working correctly” here. It means the particle has an overall positive electrical charge because it has lost negative charge.
Example Sentence 1
When the battery discharges, metal atoms in the plates lose electrons and become positive ions.
Example Sentence 2
In battery systems, positive ions move to help complete the flow of electricity.