Matter And 1. Energy

Chapter 1 Topics:Chapter 1:1.Matter andEnergy2.3.4.Matter and its ClassificationPhysical and Chemical Changes andProperties of MatterEnergy and Energy ChangesScientific Inquiry1Chapter 1 Math Toolboxes:21.1 Matter and it’s Classification1.1 Scientific Notation-- Also called exponential notation1.2 Significant Figures1.3 Units and Conversions Matter is anything that occupiesspace and has mass. Forms of energy are NOTmatter. Heat and light, forexample, do not occupy spaceand have no mass. Consider the interactionbetween matter and energy inthis picture.34Composition of Matter We classify matter sothat we can understandit better. Composition of MatterPure Substances:Matter have the samecomposition throughout,and from sample tosample. can be further classifiedas either elements orcompounds.compounds.One way to classify matteris as pure substances ormixtures.mixtures.Pure 61

Figure 1.03Elements An element is a substance that cannot bebroken down into simpler substances evenby a chemical reaction. All known elements are organized on theperiodic table.78Elements and their Symbols Elements and their SymbolsElement symbols often consist of one or two letters ofthe element’s name.Examples: carbon: Ccalcium: CaHow do we explain that Fe is the symbol for iron? Know the names and symbols of the most commonelements indicated in the handout.pertabinfo.swf910Some Elements Which are metals and which are nonmetals?1112Figure 1.032

Compounds CompoundA compound is a pure substance composed of two ormore elements combined chemically in definiteproportions.A compound has properties that are different fromthose of its component elements. Pure sand is thecompound silicondioxide, SiO2.Fig. 1.5Figure 1.01Compound: Iron pyrite, Fe2S3Elements: Iron, Fe, and Sulfur, S13Elements and Compounds 14Figure 1.07Identify each of the following as an elementor compound.1.2.3.4.classify-matter.swfHeH2Osodium chloridecopper15Salt Being Separated by Evaporationfrom the Great Salt LakeMixtures A mixture is a combination of two or moreelements or compounds .Mixtures differ from pure compounds in thatthat their components can be separated byphysical processes. Examples: 16Pencil leadSalt waterAir17Figure 1.06183

MixturesMixtures Mixtures can be furtherclassified ashomogeneous andheterogeneous.Homogeneous mixtureshave the samecomposition throughout.Heterogeneous mixturesdo not.Classify each of the following mixtures ashomogeneous or heterogeneous:heterogeneous: Mixtures HomogeneousHeterogeneous Salt waterLake waterTap waterAirBrass (an alloy of copper and zinc)Potting soilCake mix19MolecularMolecular-Level Representations of Matter– Copper AtomsRepresentations of Matter 20Macroscopic – we can see with our eyesMolecular level – a magnification to a levelthat shows atomsAtom – the smallest unit of an element;represented as single sphere.Molecule – two or more bound atomsFigure 1.082122MolecularMolecular-Level Representations of Matter– Helium AtomsMolecularMolecular-Level Representations of Matter– water moleculesFigure 1.0923Figure 1.10244

Molecular-Level Representations Does this imagerepresent atoms ormolecules? Is this an element,compound, or mixture?Different Ways to Represent WaterFigure 1.12Figure 1.112526Classify each of the following as anelement, compound, or mixture.States of Matter A different way to classify matter is by itsphysical state: solid, liquid, or gas. What are the macroscopic properties of each? How do the atoms and molecules of solids,liquids, and gases behave differently?Change of State27Solid and Liquids States of CopperFigure 1.142928Gases can be CompressedFigure 1.15305

Water vapor condenses from the aironto the cold surface of the glass.Table 1.03Figure1.1631321.2 Physical and Chemical Changesand Properties of Matter Math Toolbox 1.3A physical property is a characteristic that we canobserve without changing the composition of asubstance.Examples Units and ConversionsMetric Base Units and Derived Units Length: meter (m) Mass: kilogram (kg) Time: second (s) Temperature: Kelvins (K) Mole: molColorqualitative propertiesOdorMassVolumequantitative propertiesDensityTemperature33Conversion(Math Toolbox 1.3)(& back cover of text)Mass 34We usually measure themass of an object byweighing it on abalance.How many milligramsin a gram?How many grams in akilogram?Prefixes (Table 2.3) Length measurementsgigaG1091 Gg 109 ggigamegaM1061 Mg 106 gmegakilok1031 kg 103 gkilocentic10-21 cg 10-2 gcenti3millim101 mg 10-3 gmilli6microμ101 μg 10-6 gmicro9nanon101 ng 10-9 gnano12picop101 pg 10-12 gpico35366

Conversion(Math Toolbox 1.3)(& back cover of text)Mass Unit Conversions(Math Toolbox 1.3)Prefixes (Table 2.3) Length measurementsgigaG1091 Gm 109 mgiga6megaM101 Mm 106 mmega3kilok101 km 103 mkilo2centic101 cm 10-2 mcentimillim10-31 mm 10-3 mmillimicroμ10-61 μm 10-6 mmicronanon10-91 nm 10-9 mnano12picop101 pm 10-12 mpico- Convert 12.0 grams to milligrams. Convert 12.0 grams to ounces (1 oz 28.34 g)3738Math Toolbox 1.1 Math Toolbox 1.2 Scientific Notation Significant Figures Powers of Ten (Slide Show)Show).0.000523 5.23 5.23 10 4 All nonnon-zero digits are significant. (435 g)A zero that falls between two significant digits issignificant. (405 g; 40.5 g)Zeros to the right of a sig. digit and to the right of adecimal pt. are significant. (5.00 g)Zeros to the left of the first significant digit are notsignificant. (0.151 g; 0.00405 g)If a number is 1, the zeros to the right of the lastnonzero digit may or may not be significant. Usescientific notation to specify.3940Volume VolumeWe can measure the volume of a cube bymeasuring the length of one of its sides, andthen cubing the length. If the length of a sideis 2.0 cm,cm, what is the volume of this cube? Volumes of liquids are usually measured in units ofmilliliters (mL).1 mL 1 cm3 exactlyHow many mL in 1 L?2.0 centimetersSome 250-mL,500-mL, and 1-Lcontainers41427

Volume Unit Conversions Convert 25.0 mL to L. Convert 25.0 mL to quarts (1 L 1.057 qt)Density The density of a substance is the ratio of its mass tovolume:massDensity volumeIf the mass of the cube is 11.2 grams, what is itsdensity?2.0 centimeters4344Gold has a greater mass than aluminum.Which cube has the greater density?Density Which liquid is the mostdense. Which is leastdense?Compare the density ofthe water and theprofessor.Figure 1.19Figure 1.2045Given that these samples of metals have thesame mass, which has the greater density?Density mass/volume 4746Why is regular sodamore dense?488

Why is ice less dense than liquid water?Temperature49Figure 1.22Temperature Scales TK T C 273.15T F 1.8(T1.8(T C) 32 Boiling Point of Water: Freezing Point of Water: Lowest Possible Temperature: Physical Changes 212 F, 100 C, 373.15 K 50A physical change is a process that changesthe physical properties of a substance withoutchanging its chemical composition.Phase changes are physical changes.32 F, 0 C, 273.15 K 273.15 C,273.15 C, 0.00 K5152Vaporization or EvaporationSublimation of Dry Ice (CO2) 53CO2(s) CO2(g)Draw a molecularmolecular-levelrepresentation for thesublimation of CO2.549

Figure 1.24Chemical Changes A chemical change is a process where one ormore substances are converted into one or morenew substances. (Also called a chemicalreaction) Examples: Pennies tarnishingBurning gasolineThe reaction of hydrogen and oxygen to form water5556Chemical ChangesChemical vs. Physical Changes5758Chemical ChangeChemical Properties Chemical Properties are descriptions of theability of a substance to undergo a chemicalchange.Examples: Figure 1.2559Hydrogen burns easily with oxygenHelium is unreactiveIron rustsSilver tarnishesGold is very unreactive6010

Is Boiling Water a Chemical orPhysical Change?Example 1.11aFigure 1.27b61621.3 Energy and Energy Changes When chemical or physical changes occur,energy changes also occur.Some processes release energy and somerequire an energy input.Examples: When wood burns with oxygen, energy in theform of heat is released.When ammonium nitrate dissolves in water in acold pack, energy in the form of heat isabsorbed.63When hydrogen burns with oxygen,energy in the form of heat is released.Figure 1.286564Electricity is used todecompose water into its elements6611

Which pair of molecules has morekinetic energy?Energy Kinetic energy – energy of motion The kinetic energy of a sample will increase astemperature is increased.Potential energy – energy possessed by anobject because of its position; stored energy As a ball is raised up in the air, its potentialenergy increases.Very reactive substances have high potentialenergy.67Units of Energy Calories (Cal); calories (cal); joules (J) The unit Calorie (Cal) is used to describethe energy content of food.68¾ One serving of thiscereal has 190 Calories.¾ What is the energycontent in units ofjoules?1 Cal 1000 cal 1 kcal4.184 J 1 cal697012

Matter is anything that occupies space and has mass. Forms of energy are NOT matter. Heat and light, for example, do not occupy space and have no mass. Consider the interaction between matter and energy in this picture. 5 Composition of Matter We classify matter so tha