Here's why:

* pH scale: The pH scale measures the acidity or alkalinity of a solution. It ranges from 0 to 14.

* Acidic: Solutions with a pH less than 7 are acidic.

* Basic (alkaline): Solutions with a pH greater than 7 are basic or alkaline.

* Neutral: Solutions with a pH of 7 are neutral. This means they have an equal concentration of hydrogen ions (H+) and hydroxide ions (OH-).

Pure water has a pH of 7.