Superacids can permanently protonate water to give ionic, crystalline hydronium salts.
Hydronium, on the other hand, has several transitions that make it a superior candidate for detection and identification in a variety of situations.
This special case of water reacting with water to produce hydronium (and hydroxide) ions is commonly known as the self-ionization of water.
In acidic solutions, hydronium is the more active, its excess proton being readily available for reaction with basic species.
The effective diameter for the hydronium ion is 9.
One can see that the one positively charged hydronium molecule and one negatively charged hydroxide molecule have formed water, which has an electrovalency of zero.
The positive hydronium ions that approach the negative cathode mostly combine with negative hydroxyl ions to form water.
While hydroiodic acid solutions are stable, the hydronium-astatide solution is clearly less stable than the water-hydrogen-astatine system.