The simplest form of the chemical equation for the self-ionization of water is:

2 H₂O ⇌ H₃O⁺ + OH⁻

Here's what it means:

* 2 H₂O: Two water molecules are involved in the reaction.

* ⇌: This symbol indicates an equilibrium reaction, meaning the reaction can proceed in both directions.

* H₃O⁺: This is the hydronium ion, formed when a water molecule accepts a proton (H⁺).

* OH⁻: This is the hydroxide ion, formed when a water molecule loses a proton (H⁺).

Explanation:

Water molecules can act as both acids and bases. In this reaction, one water molecule acts as an acid, donating a proton (H⁺) to another water molecule, which acts as a base. This results in the formation of hydronium ions (H₃O⁺) and hydroxide ions (OH⁻).