2Matter and Change 2.1 – Properties of Matter 2.2 – Mixtures 2.3 – Elements and Compounds2.4 – Chemical Reactions
3ObjectivesDifferentiate and give examples of extensive and intensive propertiesDistinguish the three primary states of matterDistinguish physical from chemical change.Classify mixtures as homogeneous or heterogeneous.Distinguish between elements and compounds.Memorize the 24 most encountered elements names and symbols.Distinguish chemical from physical properties
4Extensive Properties Mass - amount of matter of an object. Volume - the space occupied by an object.Extensive Property - a property that depends on the amount of matter in a sample.
5Intensive Propertiesa property that depends on the type of matter, not the amount of matter.Example:Hardness of a rockBoiling point
6SubstancesMatter that has a uniform and definite composition
7Physical PropertiesCan be observed or measured without changing the composition of a substanceCan be used to identify substancesExamples:HardnessColorMalleabilityBoiling Point
9Physical ChangesSome properties of the material may change, but the composition stays the sameCan be reversible or irreversibleExamples:BoilFreezeBreakCrush
10States of Matter Solid Liquid Gas Definite shape and volume Particles are highly organized and packed close togetherNot easily compressedLiquidDefinite volume; takes the shape of its containerParticles are tightly packed together, but arranged randomlyGasTakes the shape and volume of its containerParticles are spaced very far apartEasily Compressed
17Mixture physical blend of two or more components heterogeneous mixture – composition is not uniform throughout (2 or more phases/part)homogeneous mixture – the composition is uniform throughout is a (single phase/part)Also known as a solution.
18Separating MixturesFiltration - separates a solid from the liquid in a heterogeneous mixtureDistillation – a liquid is boiled to produce a vapor that is then condensed into a liquid.
19Elements vs. Compoundselement – the simplest form of matter that has a unique set of properties.compound – a substance that contains two or more elements chemically combined in a fixed proportion.Properties of the individual components are different than the properties of the compound
20Distinguishing Substances & Mixtures The flow chart summarizes the process for classifying matter. Any sample of matter is either an element, a compound, or a mixture. Interpreting Diagrams What is the key difference between a substance and a solution?
22Chemical Reactions Chemical Property ability of a chemical to undergo a chemical changeReactant – substances that undergo changeProducts – New substancesChemical Change – a substance changes composition and becomes something different
23Chemical Changes Evidence of a change produces matter with a different composition than the original matterEvidence of a changeEnergy TransferColor ChangeProduction of gasProduction of a precipitateEnergy Transfer – heat (gets hot or cold), light, soundPrecipitate – a solid that settles out of solution
24Law of Conservation of Mass Matter is neither created or destroyed; it is only changedMass of the products = Mass of the reactants