Here's why:
* Pure substances are made up of only one type of particle. This means they have a fixed composition and uniform properties throughout.
* Physical separation methods like filtration, distillation, evaporation, and magnetism work by exploiting differences in physical properties like boiling point, density, or magnetic attraction.
* If a substance cannot be separated by these methods, it implies that its components have identical physical properties, making it a single, pure substance.
Examples of pure substances include:
* Elements: like gold (Au), oxygen (O2), and carbon (C)
* Compounds: like water (H2O), salt (NaCl), and sugar (C12H22O11)
