Definition
A positively charged ion. An atom or molecule that has lost one or more electrons, giving it a net positive electrical charge. In an electrolyte, cations migrate toward the negative electrode (cathode) when an electric current is applied.
Plain English
An atom that has lost one or more of its electrons and now carries a positive electrical charge. Because it is positive, it moves toward the negative side of a battery or electrical cell.
Context Anchor
Seen in aircraft battery, charging, electrolyte, and corrosion discussions.
Derivation
From the Greek 'kation,' meaning 'going down.' The term was coined in the 1830s for the ion that travels toward the cathode (the negative electrode) during electrolysis. Knowing it 'goes to the cathode' is the easiest way to remember which charge it carries.
Why Pilots Care
Aircraft batteries depend on controlled cation movement during charge and discharge cycles to maintain reliable electrical power for instruments, radios, and engine starting.
Intuition Check
Do not think of a cation as just any charged particle. A cation is specifically the positive kind, caused by losing electrons.
Example Sentence 1
When the battery discharges, cations move through the electrolyte toward the negative plate.
Example Sentence 2
Maintenance checks include inspecting for cation buildup that can reduce battery performance over time.