Characteristics of Pure Substance:
1. Definite Composition:
- A pure substance is composed of only one type of particle, either atoms or molecules, with a fixed chemical composition. This means that the ratio of elements in a pure substance is always constant.
2. Distinct Properties:
- Pure substances have unique physical and chemical properties that distinguish them from mixtures. These properties remain constant regardless of the sample size.
3. Homogeneity:
- Pure substances are uniform throughout, meaning that they have the same composition and properties in all parts of the substance. This homogeneity allows for consistent behavior under different conditions.
4. Fixed Melting and Boiling Points:
- Pure substances have well-defined melting and boiling points, which remain constant under specific pressure conditions. These characteristic temperatures are used to identify and classify pure substances.
5. Crystalline Structure:
- Many pure substances exhibit a regular and repeating atomic or molecular arrangement known as a crystalline structure. This structure contributes to the unique properties of pure substances.
6. Undergo Definite Chemical Reactions:
- Pure substances react in a specific and predictable manner with other substances due to their fixed composition. This allows for the identification and classification of pure substances based on their chemical reactivity.
In conclusion, pure substances exhibit a set of characteristic properties that distinguish them from mixtures. These properties include definite composition, distinct properties, homogeneity, fixed melting and boiling points, crystalline structure, and definite chemical reactions. Understanding these characteristics is essential for the identification and classification of pure substances in various scientific fields.