The pH scale measures the concentration of hydrogen ions (H+) in a solution.

Here's a breakdown:

* pH stands for "power of hydrogen."

* Hydrogen ions (H+) are positively charged ions that are present in all aqueous solutions.

* A higher concentration of H+ ions means a lower pH value, indicating a more acidic solution.

* A lower concentration of H+ ions means a higher pH value, indicating a more alkaline (basic) solution.

The pH scale ranges from 0 to 14, with:

* 0 being the most acidic

* 7 being neutral (like pure water)

* 14 being the most alkaline