What is a solution with a pH of less than 7.0 classified as?

A solution with a pH of less than 7.0 is classified as an acid. The pH scale ranges from 0 to 14, with values below 7 indicating acidity, values at 7 indicating neutrality, and values above 7 indicating alkalinity. In chemistry, acids are characterized by their ability to donate protons (H+) in a solution, which leads to a lower pH. This property of acids is essential in various hair coloring and chemical processes in the salon industry, as understanding the pH level can greatly affect both the application and the outcome of hair treatments.

For hair coloring specifically, products with lower pH values can help in the opening and closing of the hair cuticle, influencing how color adheres to the hair and how long it lasts. Thus, recognizing that a pH below 7 identifies an acidic solution is crucial for effective hair coloring practices.