What pH level indicates that a substance is acidic?

A pH level of 0 indicates that a substance is highly acidic. The pH scale ranges from 0 to 14, with values below 7 considered acidic, values above 7 considered basic (or alkaline), and a pH of exactly 7 being neutral. Therefore, a pH of 0 reflects a very strong acidic nature, typically associated with substances like hydrochloric acid. Understanding the pH scale is important in various fields, including medicine and environmental science, as it helps assess the acidity or alkalinity of different solutions, which can influence their behavior and interactions.