Who discovered ions?

Answer 1

Svante Arrhenius, a Swedish chemist who lived at the end of the 19th Century. He invented the idea that acids are hydrogen ions, H+, and anions, that bases are hydroxide ions, OH- and cations, that acids and bases neutralize one another to form salts, which consist of cations and anions, and water, H2O.

His idea was new, and people resisted it, because about 1825, a Danish chemist, Jon Jacob Berzelius, put forth the idea that every single kind of compound, organic and inorganic, was held together by the electrical attraction of plus atoms and minus atoms (Electrochemical theory). When people pointed out that sugar couldn't be explained that way, Berzelius insisted that it could, and people weren't looking hard enough.