MatterMatter

chapter 3chapter 3

MatterMatter

Anything that has massmass and occupies spacespace

–MassMass is measured in gramsgrams or kilogramskilograms

–Space or volumevolume is measured in litersliters or cmcm33

PhasesPhases• SOLIDS• LIQUIDS• GASES

Solid:Solid: •definite volume •definite shape

LiquidLiquid

•definite volume •indefinite shape

•takes the shape of container

GasGas

•indefinite volume •indefinite shape

•takes the shape and volume of container

States of Matter

1. How are the particles packed in each phase?

2. How do the particles move in each phase?

3. Why do liquids and gases flow?4. Why are gases so easy to compress?

4th Phase of matter

•PlasmaPlasma •exists in stars •electrons are stripped from atoms

Physical PropertiesPhysical Properties•Describe the appearance

and form of matter

Words:Words: • color, texture, luster, odor, solid, liquid, gasMeasurements:Measurements:

• a number and a unit

Intensive propertiesIntensive properties–Physical ConstantsPhysical Constants – independentindependent of sample size

•Density, freezing point, and melting point

•Solubility in water (g/ml)

Extensive PropertiesExtensive Properties

•Mass volume •depends on amountamount of matter in sample

•Extensive propertiesExtensive properties depend on quantity of matter

Chemical PropertiesChemical Properties•Describe how matter behaves

in presence of other matter•Describe how matter changes

into another kind of matter– Flammability– Resistance to corrosion– Ability to neutralize acids or

bases

Properties of CopperProperties of CopperPhysical Prop.

• Reddish brown• Shiny• Malleable• Ductile• Good Conductor• Density = 8.92

g/cm3

• mp = 1085C• bp = 2570C

Chemical Prop.• Reacts to form

green copper carbonate

• Forms a deep blue solution when in contact with NH3

• Forms new substances with HNO3

Physical ChangePhysical Change•The form or appearance of sample

may change but identityidentity remains same– Cutting, crushing, grinding,tearing– Phase changes– Dissolving

Dissolving

•Dissolving is physical change•Think of sugar in water

•still have sugar – you just spread it out with water molecules in between

C6H12O6(s) C6H12O6(aq)

Phase Changes•Phase changes are physical

changes•No new substance is created

(chemical formula stays the same)Ex:

• ice melting: H2O(s) H2O(l)

•water boiling: H2O (l) H2O(g)

Chemical ChangeChemical Change•chemical change - identity of

matter is changed•new substance with unique

properties is formed•The chemical formula changes•Ex: 2H2O(l) 2H2(g) + O2(g)

Burning• Common name for oxidation reactionoxidation reaction• Burning means reacting with oxygen• Burning is chemical change, because

original substance is changed into new kinds of matter

Ex: CH4(g) + 2O2(g) CO2(g) + 2H2O(g)

What kinds of matter are there?

Matter

Substances Mixtures

Elements CompoundsHeterogeneousMixtures

HomogeneousMixtures

Mixtures Separated by physical methodsCompounds Separated by chemical methods

ElementElement

•Substance that:•cannot be broken down or

decomposed into simpler substance•only 1 kind of atom•has definite properties

•Formulas have 1 uppercase letter

Element Song

AtomAtom

•smallest particle of element that retains properties of element

•smallest particles of element that can undergo a chemical reaction

CompoundsCompounds• 2 or more elements chemically

combined in a definite ratio• Properties are differentdifferent from those of

elements formed from• Homogeneous• Broken into elements by chemical

decomposition reaction• Formulas have 2 or more uppercase

letters

2Na + Cl2 2NaCl

MixturesMixtures

•Combo of 2 or more pure substances

•Physically combined notnot chemically combined

•Each substance retains its own identity and properties

MixturesMixtures•Variable composition•No unique properties

(Think of sugar and salt mixed together)

•Separated by physical methodsphysical methods•May be homogeneous or

heterogeneous

TypesTypes of Mixtures of Mixtures

• Homogeneous: constant composition throughout, single phase– Ex: Solutions (all 3 phases) such as air, windex, kool-aid

• Heterogeneous: See a boundary or regions that look differentEx: ice water, granite

Suspensions, Colloids

Suspensions• particles in suspensions are larger

than those in solutions• components of suspension can be

evenly distributed by mechanical means (shaking the contents) but components will settle out

Colloids• particles larger than size of molecule but

smaller than particles seen with naked eye

• colloidal dispersion– consists of colloids in a dispersing medium

• Ex: whipped cream, mayonnaise, milk, butter, gelatin, jelly, colored glass

Colloid subtypes

Aerosols: –solid or liquid particles in gasEx: •Smoke: solid in a gas•Fog: liquid in a gas

Sols: –solid particles in a liquidEx: •Milk of Magnesia (solid magnesium hydroxide in water)

Emulsions: –liquid particles in liquidEx: •Mayonnaise: oil in water

Gels: –liquids in solidEx: •Gelatin: protein in water •Quicksand: sand in water

Hints for MixturesHints for Mixtures• Solutions in gas & liquid phases transmit light

• particles not big enough to scatter light • look translucent

• Suspensions look cloudy • particles big enough to scatter light• settle on standing

source source

CuSO4(aq)

Particle Diagrams

Atoms of a monatomic element

Molecules of a diatomic element

Particle Diagrams

Molecules of a triatomic compound

Mixture: monatomic element, diatomic element, triatomic compound

Separating MixturesSeparating Mixtures• Physically combined• Separation based on physical properties

– Sorting: size & appearance– Filtration: size solid in liquid– Distillation: different bp’s liquids mixed– Crystallization: solubility solid in liquid– Magnet: magnetization – Chromatography: solubility liquids mixed

– “Travel” ability

source

Distillation

Paper Chromatograhy

Crystallization

Conservation of MassConservation of Mass

Mass before = Mass after

# of atoms before = # of atoms after