What does the pH scale measure?

The pH scale is a measure that specifically quantifies the acidity or basicity of a solution. It operates on a logarithmic scale typically ranging from 0 to 14, where a value of 7 is considered neutral, values lower than 7 indicate acidity (higher concentrations of hydrogen ions), and values above 7 indicate basicity (higher concentrations of hydroxide ions).

Understanding the significance of the pH scale is essential in various chemical applications, including biological systems, environmental science, and industrial processes, where the acidity or basicity can greatly affect reactions and behaviors of substances in solutions. Hence, the correct choice accurately reflects the role of the pH scale in chemistry.