Classification of matter: elements, compounds, mixtures

1. Introduction to Matter

1. Matter is anything that has mass and occupies space.
2. It is composed of atoms, molecules, or ions.
3. Matter can be classified based on its composition.

2. Classification of Matter

1. Matter is broadly classified into pure substances and mixtures.
2. Pure substances are further divided into elements and compounds.

3. Elements

1. An element is a pure substance that cannot be broken down into simpler substances by chemical methods.
2. Elements are composed of only one type of atom.
3. They are represented by symbols (e.g., H for Hydrogen, O for Oxygen).
4. Examples include gold (Au), iron (Fe), and carbon (C).
5. Elements are classified into metals, non-metals, and metalloids.

4. Compounds

1. A compound is a pure substance made of two or more elements chemically combined in a fixed ratio.
2. Compounds have different properties from their constituent elements.
3. They can be broken down into simpler substances by chemical methods.
4. Examples include water (H₂O), carbon dioxide (CO₂), and sodium chloride (NaCl).

5. Mixtures

1. A mixture consists of two or more substances physically combined, not chemically bonded.
2. Substances in a mixture retain their individual properties.
3. Mixtures can be homogeneous or heterogeneous.

6. Homogeneous Mixtures

1. Components are evenly distributed, and the mixture appears uniform.
2. Examples include saltwater, air, and alloys.
3. Also called solutions.

7. Heterogeneous Mixtures

1. Components are unevenly distributed, and the mixture has a non-uniform appearance.
2. Examples include sand and water, oil and water, and salad.
3. Individual components can often be separated by physical methods.

8. Separation Techniques

1. Mixtures can be separated using physical processes such as filtration, distillation, and evaporation.
2. Compounds require chemical reactions for separation into elements.

9. Applications

1. Understanding the classification of matter helps in material synthesis, chemical analysis, and industrial applications.
2. Mixtures are widely used in food processing, medicine, and engineering.