Ionization

Ionization is the separation of an atom or molecule into positive and negative ions.

Some water (H2O) molecules naturally ionize into hydrogen ions and hydroxide ions. The pH scales measure these ions.

HYDROGEN ION (H+)

The hydrogen ion is acidic. The more hydrogen ion dare there in a substance, the more acidic it will be.

HYDROXIDE ION (H-)

The hydroxide is alkaline. The more hydroxide ion there are in an substance, the more alkaline it will be.

pH is only possible because of water. Therefore, only products that contain water can have a pH.