(a) Ice (b) Milk (c) Iron (d) Hydrochloric acid (e) Calcium oxide (f) Mercury (g) Brick (h) Wood (i) Air
Materials that fall in the category of a “pure substance” are Iron, Hydrochloric acid, Calcium oxide, Mercury.
Difference Between Pure and Impure Substance
| Characteristic | Pure Substance | Impure Substance |
| Particle Type | Consists of only one type of particle (atoms or molecules) | Composed of two or more different types of particles (may be elements or compounds) |
| Composition | Constant and definite composition throughout | Composition may vary |
| Properties | Distinct physical and chemical properties | Properties may vary throughout the sample |
| Examples | Elements (e.g., gold, oxygen) | Mixtures (e.g., air, seawater), alloys (e.g., brass) |