対たいイオンMeanings1nouncounter ionTechnical term in chemistry and physics for the ion that accompanies another ion to maintain electrical neutrality.界かい面めん活かっ性せい剤ざいの対たいイオンが溶よう液えきの性せい質しつに影えい響きょうを与あたえる。The counter ion of the surfactant affects the properties of the solution.