Heterogeneous Mixture
* Definition: A mixture where the components are not evenly distributed and can be visually distinguished.
* Composition: Made up of two or more substances that retain their individual properties.
* Appearance: Non-uniform appearance. Different parts of the mixture will look different.
* Examples:
* Sand and water
* Oil and water
* Salad dressing
* Granite rock
Pure Substance
* Definition: A substance that has a fixed composition and consistent properties throughout.
* Composition: Made up of only one type of atom or molecule.
* Appearance: Uniform appearance. All parts of the substance look the same.
* Examples:
* Water (H₂O)
* Gold (Au)
* Sugar (C₁₂H₂₂O₁₁)
* Table salt (NaCl)
Key Differences
* Uniformity: Heterogeneous mixtures are non-uniform, while pure substances are uniform.
* Separation: Components of a heterogeneous mixture can often be separated by physical means (e.g., filtering, decanting). Pure substances cannot be separated by physical means alone.
* Composition: Heterogeneous mixtures have variable compositions, while pure substances have fixed compositions.
In Summary
Think of it like this: A heterogeneous mixture is like a salad – you can see the different ingredients. A pure substance is like a glass of water – it looks the same throughout.
