The scale that measures the concentration of hydrogen ions in a solution is the pH scale.

Here's a breakdown:

* pH stands for "power of hydrogen".

* It is a logarithmic scale that ranges from 0 to 14.

* Lower pH values indicate a higher concentration of hydrogen ions, meaning the solution is more acidic.

* Higher pH values indicate a lower concentration of hydrogen ions, meaning the solution is more basic (alkaline).

* A pH of 7 is considered neutral.

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