2 Composition of Matter – Sec. 1 Pure SubstancesSame composition throughoutEither an element or compoundElementAll one type of atomEverything made of atomsCompoundAtoms of two or more elements chemically bonded together
3 Composition of Matter Mixtures Heterogeneous Mixture Made of two or more substances that can be easily separated by physical meansHeterogeneous MixtureDifferent materials can be seen easilyGranite, concrete, vegetable soupHomogeneous Mixture (Solution)Blended evenly throughoutVinegar, Kool-aid
5 Mixtures Colloid ~ heterogeneous Detecting Colloids Particles larger than solution but not heavy enough to settle outMilk, paint, fog and smokeDetecting ColloidsPass a beam of light through itColloid – See beamSolution – Cannot see beamParticles big enough to scatter light – Tyndall Effect
6 Mixtures Suspension ~ heterogeneous Not solution, not colloid Muddy pond waterHeterogeneous mixture with a liquid and visible particles that settle
12 Physical Change How to get pure water from salt water? Distillation – evaporate liquid and then recondense it
13 Chemical Properties and Changes Chemical Property – can be observed only by changing the substanceFlammability, reactivity, decompositionChemical Change – change where a NEW substance is formedWeathering – Physical or Chemical Change?Both!
14 Law of Conservation of Mass Matter is neither created nor destroyed during a chemical reactionMass of all substances before = mass of all substances after change