PH Scale - GCSE Chemistry Definition

The pH scale is a measure of how acidic or alkaline a substance is. It goes from 0 to 14, with pH 7 being neutral, like pure water. Substances with a pH less than 7 are acids, such as lemon juice or vinegar. Substances with a pH greater than 7 are alkalis (a type of base), such as soap or baking soda. The pH scale is important in chemistry because it helps to identify the properties of a substance and predict how it will react. In GCSE Chemistry, students use indicators or pH meters to measure the pH of solutions.