What is a base characterized by in terms of pH?

A base is characterized by a pH greater than 7. The pH scale measures the acidity or basicity of a solution, with values ranging from 0 to 14. A pH of 7 is considered neutral, which is typical of pure water. When the pH exceeds 7, it indicates a basic (or alkaline) solution. Bases, such as sodium hydroxide or ammonia, accept protons or release hydroxide ions in solution, which leads to this increase in pH. This property is fundamental in chemistry and is critical in various applications, including those related to hazardous materials, as understanding the pH levels can help assess chemical properties and risks associated with exposure to substances.