what is a ph scale? state its maximum and minimum value.
A pH scale is a measure of how acidic or basic a substance is (pH stands for 'potential of Hydrogen'). The pH scale formally measures the activity of hydrogen ions in a substance or solution, which approximates the concentration of hydrogen ions under low concentrations.
The minimum value is 0 and the maximum is 14, i.e the pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic.