Classifying Matter Mixtures and Pure Substances What do these two photos have in common? A fisherman using a dip net to separate big fish from smaller fish or water Equipment used in crime labs to identify types of matter from a crime scene They both use properties to separate mixtures of matter into their parts The dip net uses size and state to separate the big fish from small fish and water The crime lab equipment uses various properties to gather evidence about a crime Mixtures Matter that can be physically separated into parts is a mixture Mixtures can be made up of 2 or more types of matter EXAMPLE: Salt water The salt is dissolved in the water, but it CAN be separated Remember the video we watched? Mixture Example: Concrete Concrete is a mixture of lime (CaO), cement, water(H 2 O), sand, and other ground-up rocks and solids. Workers pour the concrete into a mold and the concrete turns into a solid (as the cement solidifies) with the separate pieces inside. However, the concrete can be broken down through grinding or crushing to separate all the parts Mixture Example: Iron and Sand Pure Substances Matter that is NOT a mixture is a pure substance A pure substance is made up of only ONE type of matter, so it cant be physically separated into parts EXAMPLE: Distilled drinking water (pure water), H 2 O Examples of pure substances Sugar, C 6 H 12 O 6 Copper, Cu Pure Substances Each part of a pure substance has the same properties, because each pure substance is made up of its own type of particle The kind of particle that makes up one pure substance is different from the kind of particle that makes up another pure substance Distilled water particles:Aluminum particles: Two types of pure substances Compound: a pure substance that CAN be broken down using chemical reactions Element: a pure substance that CANNOT be broken down any further Why can compounds be broken down into smaller parts? Compounds CAN be broken down into smaller parts during chemical reactions because they contain more than one type of element EXAMPLE: Table salt (NaCl) is made of two elements: sodium and chlorine Sodium metal (Na) + Chlorine gas (Cl) Table salt (NaCl) A compound can be broken down, but an element cant Table salt (NaCl) can be broken back down into Na and Cl using chemical reactions However, the Na and Cl cant be broken down any further THINK: Elements are like the letters of the alphabet, and compounds are like the words we make out of them We can break a word down into its letter parts, but we cant break down the letters