What does pH measure?

pH measures the acidity or basicity of a substance by quantifying the concentration of hydrogen ions (H⁺) in a solution. The pH scale ranges from 0 to 14, with values less than 7 indicating acidic conditions, values equal to 7 representing a neutral solution, and values greater than 7 signifying basic (or alkaline) conditions. This measurement is crucial in various fields, including environmental science, chemistry, biology, and agriculture, as the pH of a solution can affect chemical reactions, biological processes, and the solubility of nutrients and contaminants. Understanding pH is vital for maintaining healthy ecosystems, assessing water quality, and managing agricultural soils, making it an essential concept in environmental science.