3Its all matterEverything around you is matter… even things you do not see like air and microbesA Substance is matter that has a uniform and unchanging chemical compositionTable salt or NaCL, (Sodium Chloride) is a substanceSea water isNot a substance
4Substances are key in chemistry Substances change into different substances.
5Physical PropertiesA Physical Property is a characteristic that can be observed or measured without changing the samples compositionPhysical properties can describe matter and substancesExamples: Density, Color, Odor, Taste, Hardness, Melting Point, Boiling Point
7Chemical Properties Another property of matter are chemical properties Chemical Properties are the ability of a substance to combine with or change into one or more substances
8States of Matter All matter exists as one of three physical forms Solids – a form of matter that has its own definite shape and volumeWood, Iron and Paper are examplesThe particles of a solid are packed tightly together and when heated they expand
9LiquidLiquids are a form of matter that flows, has constant volume and takes the shape of its containerEx. Water, Blood, MercuryThe particles in a liquid arenot held rigidly together and areless closely packed than solids and can move past each other.
10GasA gas is a form of matter that expands to fill the entire containerThe particles of gas are very far apart compared to liquids and solidsGases can be compressed because they are so far apartVapor is the gaseous state of a substance that is solid or liquid at room temperature
11workClassify the 3 following events as physical or chemical properties.1. Water and oil not mixing together2. A screwdriver rusting due to being outside3. Vinegar and Baking soda reacting to make a “volcano”4. Which of the following pictures shows a solid, which a liquid, which a gas?A B C.
12AnswersClassify the 3 following events as physical or chemical properties.1. Water and oil not mixing together physical2. A screwdriver rusting due to being outside chemical3. Vinegar and Baking soda reacting to make a “volcano” chemical4. Which of the following pictures shows a solid A, which a liquid C, which a gas BA B C.
13Changes in MatterCopper can undergo physical changes and chemical changesPhysical: It can be drawn outinto a wireChemical: When combinedwith Ammonia it turns aBlue-ish color
14Physical ChangeChanges which alter a substance without changing its composition are physical changes.Ex. Cutting a piece of paper, breaking a crystalName some other physical changes
15Phase changes – a form of physical change As temperature and/or pressure change substances can change forms or phasesAt 0° Celsius water or H2O exists as a solid, known as iceAs heat is added the ice melts it becomes liquid water.When the temperature of the liquid water reaches 100 ° Celsius it changes again it Vapor, the gaseous form of waterThese changes are physical because even though the water in different states has different appearances, it is still water, H2O
16Phase Change Vocabulary The words; Boil, Freeze, Condense, Vaporize, or Melt, are referring to phase changesPhase changes indicate matter changing from liquid to gas, solid to liquid, etc.
17Chemical ChangesA process that involves one or more substances changing into new substances is a chemical change or chemical reactionSubstances formed in the reaction have different compositions and different properties than the starting substances
18Evidence of Chemical Reactions Always produces a change in propertiesSOMETHING NEW!!!!
19Law of Conservation of Mass Mass is neither created nor destroyed during a chemical reactionMass of reactants = Mass of ProductsDiscovered in the 1700s by Antoine Lavoisier
20ExampleIn an experiment, 10.0g of red mercury (II) oxide powder is placed in an open flask and heated until it is converted to liquid mercury and oxygen gas. The liquid mercury has a mass 9.26g. What is the mass of the Oxygen gas formed in the reaction?Remember the Law Of Conservation OF Mass.
21More work Identify the following as physical or chemical changes 1. Liquid Nitrogen is released on the floor of the classroom, it quickly evaporates and is suddenly gone.2. A firework is lit and quickly launches into the air and then explodes into a beautiful red circle.3. You are having a glass of iced tea on a hot summer day, you suddenly notice your glass is “sweating” and is covered with tiny drops of water outside the glass
22More Answers Identify the following as physical or chemical changes 1. Liquid Nitrogen is released on the floor of the classroom, it quickly evaporates and is suddenly gone. physical2. A firework is lit and quickly launches into the air and then explodes into a beautiful red circle. chemical3. You are having a glass of iced tea on a hot summer day, you suddenly notice your glass is “sweating” and is covered with tiny drops of water outside the glass physical
23Classifying MatterWe classify matter as either Substances (having a uniform composition) and Mixtures.Mixtures are a combination of two or more pure substances in which each pure substance retains its own properties
24Heterogeneous Mixtrues Heterogeneous Mixtures do not blend smoothly throughout and individual substances are visible
25Homogeneous MixturesHomogeneous mixtures have the same composition throughout and always have a single phase.Also referred to as solutions
27Different types of solutions Gas-Gas - air is a mix of Nitrogen, oxygen, and argon gasesGas-Liquid - Carbonated beveragesSolid-Liquid - Kool-Aid contains sugar and other solids in waterSolid-Solid – Steel is an alloy of iron containing carbon
28Separating Mixtures – most matter exists as mixtures Filtration – using paper or anotherporous material to separate heterogeneousmixturesDistillation – uses differences ofboiling points of liquids to separatea homogeneous mixture of liquids
29Separating MatterCrystallization – forming solids from a liquid solution containing solidsChromatography – separates components of a mixture on tendency to move across another material ( not covered butYou should remember this)
30Elements and Compounds An element is a pure substance which can not be separated into a simpler form by physical or chemical means91 naturally occurring elements on earth(Copper, Gold, Silver, Hydrogen etc.)Each has a one or two letter symbolAu= gold, O= oxygen, Hg = Mercury, C= carbon
31CompoundsCompounds are combinations of two or more different elements that are combined chemicallyWater, table salt, aspirin are all compoundsTable Salt = Sodium (Na) Chloride (Cl) or NaClWater = Di-Hydrogen (H2) Oxide (O) or H2O