Chapter 2 Matter and Change

What is Chemistry?Using all of the letters in the word chemistry, describe your expectations from this course.

Chapter One:Matter & ChangeCreated by: Stephen CottonEdited by: Corey Nichols

2Chemistry Is a Physical ScienceChemistry is the study of the composition, structure, and the properties of matter and the changes it undergoes.There are 6 main branches of chemistry:Organic, Inorganic, Physical, Analytical, Biochemistry, and TheoreticalBranches of ChemistryBranchArea of InterestOrganicCarbon compoundsInorganicNon-carbon compoundsPhysicalProperties, changes, relationships between energy and matterAnalyticalIdentification of composition of compoundsBiochemistrySubstances/processes in living thingsTheoreticalMath & computers to predict propertiesResearchScientists are constantly searching for answers to common and complex questions. They find their answers using research.Basic research: research done for the sake of increasing knowledge about a particular subjectApplied research: research done to solve a problemResearch (contd)Eventually, research will give rise to advancements in our everyday lives. Technological development: production and use of products that improve our quality of life.

What is matter?Matter is anything that: has mass, and takes up spaceMass = a measure of the amount of stuff (or material) the object contains (dont confuse this with weight, a measure of gravity)Volume = a measure of the space occupied by the object7Describing MatterProperties used to describe matter can be classified as:Extensive depends on the amount of matter in the sample- Mass, volume, calories are examplesIntensive depends on the type of matter, not the amount present- Hardness, Density, Boiling Point

Properties areWords that describe matter (adjectives)

Physical Properties- a property that can be observed and measured without changing the materials composition.

Chemical Properties- a property that can only be observed by changing the composition of the material.

9States of matterSolid- matter that can not flow (definite shape) and has definite volume.Liquid- definite volume but takes the shape of its container (flows).Gas- a substance without definite volume or shape and can flow.

10States of MatterSolidLiquidGasDefinite Volume?YESYESNODefinite Shape?YESNONO Will it Compress?NONOYESThree Main Phases

SolidLiquid Gas MeltEvaporateCondenseFreezeCopper Phases - Solid

Copper Phases - Liquid

Copper Phases Vapor (gas)

Physical vs. Chemical ChangePhysical change will change the visible appearance, without changing the composition of the material.Can be reversible, or irreversibleChemical change - a change where a new form of matter is formed.17MixturesMixtures are a physical blend of at least two substances; have variable composition. They can be either:Heterogeneous the mixture is not uniform in compositionChocolate chip cookie, gravel, soil.Homogeneous - same composition throughout; called solutionsKool-aid, air, salt waterEvery part keeps its own properties.19Solutions are homogeneous mixturesMixed molecule by molecule, thus too small to see the different partsCan occur between any state of matter: gas in gas; liquid in gas; gas in liquid; solid in liquid; solid in solid (alloys), etc.Thus, based on the distribution of their components, mixtures are called homogeneous or heterogeneous.

20Phase?The term phase is used to describe any part of a sample with uniform composition of properties.A homogeneous mixture consists of a single phaseA heterogeneous mixture consists of two or more phases.21Separating MixturesSome can be separated easily by physical means: rocks and marbles, iron filings and sulfur (use magnet) Differences in physical properties can be used to separate mixtures.Filtration - separates a solid from the liquid in a heterogeneous mixture 22Pure Substances Pure substances are substances that have a fixed composition.

Pure substances are divided into 2 main types: Elements CompoundsPure SubstancesElements- simplest kind of mattercannot be broken down any simpler and still have properties of that element!all one kind of atom.Compounds are substances that can be broken down only by chemical methodswhen broken down, the pieces have completely different properties than the original compound.made of two or more atoms, chemically combined (not just a physical blend!) 24Compound vs. MixtureCompoundMixtureMade of one kindof material Made of more thanone kind of material Made by a chemical change Made by a physical change Definitecomposition Variablecomposition Which is it?ElementCompoundMixture

Elements vs. CompoundsCompounds can be broken down into simpler substances by chemical means, but elements cannot.A chemical change is a change that produces matter with a different composition than the original matter.27Chemical ChangeA change in which one or more substances are converted into different substances.Heat and light are often evidence of a chemical change.

Properties of CompoundsQuite different properties than their component elements.Due to a CHEMICAL CHANGE, the resulting compound has new and different properties:Table sugar carbon, hydrogen, oxygenSodium chloride sodium, chlorineWater hydrogen, oxygen29Classification of Matter

FlashbackIn the following commercial, determine what type of matter is being advertised.Be sure to explain how you derived your answer.

The Periodic TableCurrently, there are 117 elementsElements have either a 1 or two letter symbol.An elements first letter always capitalized; if there is a second letter, it is written lowercase: B, Ba, C, Ca, H, HeSome names come from Latin or other languages32Elements Based on Older NamesModern NameSymbolOlder NameAntimonySbStibium*CopperCuCuprumGoldAuAurumIronFeFerrumLeadPbPlumbumMercuryHgHydrargyrumPotassiumKKaliumSilverAgArgentumSodiumNaNatriumTinSnStannumTungstenWWolfram*

Ins and Outs of the Periodic TableGroups: vertical columns of elements on the periodic table; also called familiesThere are 18 groups on the periodic table.Elements within a group share similar properties.Periods: horizontal rows of elements on the periodic table; also called series.In total, there are 7 periods on the periodic table.Types of ElementsThere are various types of elements on the periodic table.We will discuss 4 main types of elements:MetalsNonmetalsMetalloidsNoble gases

MetalsMetals: elements that are good conductors of heat and electricityFound to the left of the zig-zag lineProperties of Metals include:Luster (shininess)Solids at room temperatureMalleable (able to be hammered or rolled into thin sheets)High tensile strength; ductile

NonmetalsNonmetals: elements that are poor conductors of heat and electricity Found to the right of the zig-zag lineProperties include:BrittleCan be solid, liquid or gas at room temperature

MetalloidsMetalloids: elements that have some properties of metals and some properties of nonmetalsFound on either side of the zig-zag lineProperties include:SemiconductorsSolid at room temperature

Noble GasesNoble gases: elements that are located in Group 18 Found on the far right side of the periodic tableProperties include:Unreactive (or inert)Gases at room temperature