Introduction to Pure and Impure Substances

Introduction to Pure and Impure Substances

What is Matter?

Matter is anything that has mass and occupies space. Everything around us, including the air we breathe, the water we drink, and the food we eat, is made up of matter. Matter can exist in different states, such as solid, liquid, and gas.

Pure Substances and Mixtures

1. Pure Substances:
   A pure substance consists of only one type of particle and has a uniform composition throughout. It cannot be separated into simpler substances by physical methods. Pure substances have fixed properties such as melting point, boiling point, and density.
   Examples:

   • Elements: Oxygen (O₂), Gold (Au), Iron (Fe)

   • Compounds: Water (H₂O), Carbon dioxide (CO₂), Sodium chloride (NaCl)

2. Mixtures:
   A mixture consists of two or more substances physically combined in varying proportions. Unlike pure substances, mixtures do not have fixed properties and can be separated by physical methods such as filtration, evaporation, or distillation.
   Types of Mixtures:

   • Homogeneous Mixtures (Solutions): Uniform composition throughout (e.g., saltwater, air).

   • Heterogeneous Mixtures: Non-uniform composition with distinguishable components (e.g., sand and iron filings, oil and water).