Which of the following is true regarding the pH scale?

The pH scale measures the acidity or alkalinity of a solution, with a range that typically spans from 0 to 14. A value lower than 7 on the pH scale indicates that a solution is acidic, as the scale is designed such that values below 7 represent increasing acidity. Conversely, values higher than 7 indicate alkalinity. A pH of 7 is classified as neutral, which is the pH of pure water at 25 degrees Celsius.

In this context, a correct understanding of pH values aligns with the observation that substances with a pH of less than 7, such as lemon juice or vinegar, are acidic. This is fundamental for anyone working in utilities maintenance, where knowing the pH of water can affect treatment processes and overall water quality.