Compare and contrast pure substances vs. mixtures in science

📚 What are Pure Substances?

A pure substance is matter that has a fixed chemical composition and distinct properties. This means it's either a single element or a single compound. The composition is consistent throughout the sample.

• ⚛️ A pure substance cannot be separated into other substances by physical means.
• 🌡️ It has a definite and constant boiling point and melting point at a given pressure.
• 💎 Examples include pure gold (Au), pure water (H₂O), and diamond (C).

🧪 What are Mixtures?

A mixture is a combination of two or more substances that are physically combined. These substances retain their individual identities and properties. Mixtures can be separated by physical means.

• 🌊 Mixtures can be either homogeneous (uniform throughout) or heterogeneous (non-uniform).
• 🧲 Components of a mixture can be separated by physical methods like filtration, evaporation, or magnetism.
• 🍕 Examples include saltwater (homogeneous) and salad (heterogeneous).

📊 Pure Substances vs. Mixtures: A Detailed Comparison

🔑 Key Takeaways

• 💡 Pure substances have a fixed composition and cannot be easily separated, while mixtures are combinations of substances that can be separated physically.
• 🔬 Understanding the difference is crucial in chemistry for identifying and working with different types of matter.
• 📚 Remember the examples to help differentiate between them: pure water vs. saltwater, gold vs. a gold alloy.