Mixtures vs. Compounds: Definitions and Differences

Definitions:

• Mixtures:
  A mixture is when two or more substances come together but keep their own properties. This means you can still recognize each part in the mixture.

  Examples:

  • Air (which has different gases)
  • Salad (made up of various vegetables)
  • Sand and salt

• Compounds:
  A compound is formed when two or more elements join together in a specific way. The new substance has different properties than the individual elements.

  Examples:

  • Water (H₂O)
  • Carbon dioxide (CO₂)
  • Table salt (sodium chloride, NaCl)

Key Differences:

1. Composition:

   • Mixtures can change in their makeup and can either be mixed evenly (homogeneous) or unevenly (heterogeneous).
   • Compounds have a set structure, which we can show using chemical formulas.

2. Separation:

   • You can separate mixtures using physical methods, like filtering or boiling.
   • To separate compounds, you need chemical reactions.

3. Properties:

   • Mixtures show the properties of the substances in them. For example, you can taste the salt and feel the texture of the sand.
   • Compounds have their own unique properties that are different from the original elements. For instance, water is a liquid at room temperature, but hydrogen and oxygen are gases.

4. Example Facts:

   • In a saltwater mixture, salt can be about 3.5% of seawater by weight, but this amount can change.
   • A compound like carbon dioxide consistently has 1 carbon atom and 2 oxygen atoms, no matter where it comes from.

Conclusion:

Knowing the difference between mixtures and compounds is important in chemistry. By understanding their properties and how they work, we can learn more about matter and how it changes. This helps us get a better grasp of the building blocks of our world.