PH - GCSE Chemistry Definition

pH is a scale used to measure how acidic or alkaline a substance is. The scale goes from 0 to 14, with 7 being neutral, like pure water. If a substance has a pH less than 7, it is acidic, like lemon juice or vinegar. If the pH is more than 7, the substance is alkaline (or basic), like baking soda or soap. In the GCSE Chemistry course, you'll learn that acids have more hydrogen ions, while alkalis have more hydroxide ions. pH can affect how substances react with each other, and it's important in everyday things like food, cleaning products, and the environment.