What does the pH of a solution indicate?​

The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity of the solution.

Explanation:

The pH scale measures whether there is more hydronium or hydroxide in a solution. In other words, it tells us how basic or acidic the solution is. A lower pH means something is more acidic, also known as a stronger acid. A higher pH means it is more alkaline or a stronger base.

it's c. elements are placed in rows based on how may valencies electrons have.