What does the letter 'p' in pH stand for?

The letter 'p' in pH stands for 'potential.' This terminology originates from the German word 'Potenz,' which translates to 'power' in English but is used in the context of a power scale when applied to concentrations of hydrogen ions. The full term describes the negative logarithm of the hydrogen ion concentration in a solution, indicating the solution's acidity or alkalinity. The 'H' specifically refers to hydrogen ions, which are the determining factor in measuring acidity, while the 'p' denotes the mathematical transformation applied to the concentration, effectively expressing potential acidity. Therefore, recognizing 'potential' as the correct interpretation helps in understanding the concept of pH in scientific discussions and practical applications in fields like chemistry, biology, and skincare formulations.