counterion
/ˈkaʊntərˌaɪən/
noun
- An ion that has the opposite charge to another ion in a solution, helping to balance the electrical charge.
- Without the right counterion, the ionic compound would not dissolve properly in water.
- The chemist added a counterion to stabilize the charged molecule in the liquid.
- In a salt solution, each positive sodium ion is paired with a negative chloride counterion.