noun
ion
EYE-uhn
noun
1
An atom or molecule that has gained or lost electrons, giving it an electric charge.
"Salt dissolves in water into sodium and chloride ions."
How to Use Ion
Learner’s notesIn plain EnglishA charged particle formed when an atom gains or loses electrons.
Common pairings
positive ion
negative ion
ion exchange
Word Forms
ions plural, Ions plural
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Salt dissolves in water into sodium and chloride _____.
Etymology
Coined in 1834 from Greek ion, "going," the present participle of eimi ("I go") — chosen because ions move toward oppositely charged electrodes.