What does the pH scale measure?

The pH scale specifically measures the concentration of hydrogen ions (H⁺) in a solution, which is a key factor in determining how acidic or basic that solution is. The scale typically ranges from 0 to 14, with lower values indicating higher concentrations of hydrogen ions and thus more acidic solutions, and higher values indicating lower concentrations of hydrogen ions and more basic (alkaline) solutions. A pH of 7 is considered neutral, meaning the concentrations of hydrogen ions and hydroxide ions (OH⁻) are equal.

Understanding pH is crucial in many fields, such as chemistry, biology, environmental science, and medicine, as it influences chemical reactions, biological functions, and environmental processes. By quantifying the acidity or basicity of a solution, scientists and practitioners can predict behavior in chemical reactions, assess the health of ecosystems, and optimize conditions for biochemical processes.