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Chapter 2Chapter 2

Matter and ChangeMatter and Change

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What is Matter?What is Matter? MatterMatter is anything that takes up space is anything that takes up space

and has mass.and has mass. MassMass is the amount of matter in an is the amount of matter in an

object.object. MassMass is resistance to change in motion is resistance to change in motion

along a smooth and level surface.along a smooth and level surface. ExamplesExamples

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Types of MatterTypes of Matter SubstanceSubstance- a particular kind of matter - - a particular kind of matter -

purepure Mixture-Mixture- more than one kind of matter more than one kind of matter

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PropertiesProperties Words that describe matter (adjectives)Words that describe matter (adjectives) Physical PropertiesPhysical Properties- a property that can - a property that can

be observed and measured without be observed and measured without changing the substance.changing the substance.

Chemical PropertiesChemical Properties- a property that - a property that can only be observed by changing the can only be observed by changing the type of substance. type of substance.

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PropertiesProperties Words that describe matter (adjectives)Words that describe matter (adjectives) Extensive PropertiesExtensive Properties- only depends on - only depends on

the amount of matterthe amount of matter Intensive PropertiesIntensive Properties- only depends on - only depends on

the type of matter, not the amountthe type of matter, not the amount Used to identify a substanceUsed to identify a substance

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States of matterStates of matter SolidSolid- mater that can not flow and has - mater that can not flow and has

definite volume.definite volume. LiquidLiquid- definite volume but takes the - definite volume but takes the

shape of its container (flows).shape of its container (flows). GasGas- a substance without definite - a substance without definite

volume or shape and can flow.volume or shape and can flow. VaporVapor- a substance that is currently a - a substance that is currently a

gas but normally is a liquid or solid at gas but normally is a liquid or solid at room temperature.room temperature.

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States of MatterStates of Matter

Solid

Liquid

Gas

Definite Volume?

YES

YES

NO

Definite Shape?

YES

NO

NO

Temp. increase

Small Expans.

Small Expans.

Large Expans.

Com-pressible?

NO

NO

YES

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Solid Liquid Gas

Melt Evaporate

CondenseFreeze

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States of MatterStates of Matter There are moreThere are more PlasmaPlasma

– high temperature low pressure high temperature low pressure – electrons separate from nucleuselectrons separate from nucleus– Most common in the universeMost common in the universe

More at very low tempMore at very low temp– Bose- Einstein condensateBose- Einstein condensate– Quantum superfluidsQuantum superfluids

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Another Way to Change StatesAnother Way to Change States PressurePressure For some substances it will turn solids For some substances it will turn solids

to liquidsto liquids For others it will turn liquids to solidsFor others it will turn liquids to solids

– Silly puttySilly putty Will turn gas to liquid-Will turn gas to liquid-

– Compressor in refrigerator and ACCompressor in refrigerator and AC

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Physical ChangesPhysical Changes A change that changes appearances, A change that changes appearances,

without changing the composition.without changing the composition. Examples?Examples? Chemical changesChemical changes - a change where a - a change where a

new form of matter is formed.new form of matter is formed. Also called chemical reaction.Also called chemical reaction. Examples?Examples? Not phase changesNot phase changes

– Ice is still water.Ice is still water.

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MixturesMixtures Made up of two substances.Made up of two substances. Variable composition.Variable composition. HeterogeneousHeterogeneous- mixture is not the same - mixture is not the same

from place to place.from place to place. Chocolate chip cookie, gravel, soil.Chocolate chip cookie, gravel, soil. HomogeneousHomogeneous- same composition - same composition

throughout.throughout. Kool-aid, air.Kool-aid, air. Every part keeps its properties.Every part keeps its properties.

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Separating mixturesSeparating mixtures Only a physical change- no new matterOnly a physical change- no new matter Filtration- separate solids from liquids Filtration- separate solids from liquids

with a barrierwith a barrier Distillation- separate because of Distillation- separate because of

different boiling pointsdifferent boiling points– Heat mixtureHeat mixture– Catch vapor in cooled areaCatch vapor in cooled area

Chromatography- Chromatography- different substances different substances are attracted to paper or gel, so move at are attracted to paper or gel, so move at different speedsdifferent speeds

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ChromatographyChromatography

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PhasesPhases A part of a sample with uniform A part of a sample with uniform

composition, therefore uniform composition, therefore uniform propertiesproperties

Homogeneous- 1 phaseHomogeneous- 1 phase Heterogeneous – more than 1Heterogeneous – more than 1

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SolutionsSolutions Homogeneous mixtureHomogeneous mixture Mixed molecule by moleculeMixed molecule by molecule Can occur between any state of matter.Can occur between any state of matter. Solid in liquid- Kool-aidSolid in liquid- Kool-aid Liquid in liquid- antifreezeLiquid in liquid- antifreeze Gas in gas- airGas in gas- air Solid in solid - brassSolid in solid - brass Liquid in gas- water vaporLiquid in gas- water vapor

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SolutionsSolutions Like all mixtures, they keep the Like all mixtures, they keep the

properties of the components.properties of the components. Can be separated by physical meansCan be separated by physical means Not easily separated- Not easily separated- cancan be separated be separated

without creating anything new.without creating anything new.

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SubstancesSubstances ElementsElements- simplest kind of matter- simplest kind of matter Cannot be broken down into simplerCannot be broken down into simpler All one kind of atom.All one kind of atom. CompoundsCompounds are substances that can be are substances that can be

broken down by chemical methodsbroken down by chemical methods When they are broken down, the pieces When they are broken down, the pieces

have completely different properties have completely different properties than the compound. than the compound. SaltSalt

Made of Made of moleculesmolecules- two or more atoms - two or more atoms stuck togetherstuck together

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Compound or MixtureCompound or Mixture

Compound Mixture

One kind of piece-Molecules

More than one kind - Molecule or atoms

Making is a chemical change

Making is a physical change

Only one kind Variable composition

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Which is it?Which is it?

ElementCompoundMixture

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Chemical ReactionsChemical Reactions Another name for chemical changeAnother name for chemical change When one or more substances are When one or more substances are

changed into new substances.changed into new substances. Reactants-Reactants- stuff you start with stuff you start with Products-Products- What you make What you make NEW PROPERTIESNEW PROPERTIES Because each substance has its own Because each substance has its own

propertiesproperties

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Indications of a chemical reactionIndications of a chemical reaction Energy absorbed or releasedEnergy absorbed or released Color changeColor change Odor changeOdor change PrecipitatePrecipitate- - solid that separates from solid that separates from

solutionsolution Not easily reversedNot easily reversed Only clues not certaintyOnly clues not certainty

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Chemical symbolsChemical symbols There are 116 elementsThere are 116 elements Each has a 1 or two letter Each has a 1 or two letter symbolsymbol First letter always capitalized second First letter always capitalized second

nevernever Don’t need to memorizeDon’t need to memorize Some from Latin or other languagesSome from Latin or other languages

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Chemical symbolsChemical symbols Used to write chemical formulasUsed to write chemical formulas Subscripts tell us how many of each Subscripts tell us how many of each

atomatom HH22OO

CC33HH88

HBrOHBrO33

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Conservation of Mass Conservation of Mass Mass can not be created or destroyed Mass can not be created or destroyed

in ordinary (not nuclear) changes.in ordinary (not nuclear) changes. All the mass can be accounted for.All the mass can be accounted for. Mass at the start = mass at endMass at the start = mass at end

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EnergyEnergy The ability to do The ability to do work.work. Work - Work - cause a change or move an cause a change or move an

object.object. Many types- all can be changed into the Many types- all can be changed into the

other.other.

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Types of energyTypes of energy PotentialPotential- stored energy- stored energy Kinetic Energy-Kinetic Energy- energy something has energy something has

because its movingbecause its moving Heat-Heat- the energy that moves because of the energy that moves because of

a temperature difference.a temperature difference. Chemical energy-Chemical energy- energy released or energy released or

absorbed in a chemical change.absorbed in a chemical change. Electrical energyElectrical energy - energy of moving - energy of moving

chargescharges

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Types of EnergyTypes of Energy Radiant Energy-Radiant Energy- energy that can travel energy that can travel

through empty space (light, UV, through empty space (light, UV, infrared, radio)infrared, radio)

Nuclear EnergyNuclear Energy – Energy from changing – Energy from changing the nucleus of atomsthe nucleus of atoms

All types of energy can be converted All types of energy can be converted into others.into others.

If you trace the source far enough back, If you trace the source far enough back, you will end up at nuclear energy.you will end up at nuclear energy.

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Conservation of EnergyConservation of Energy Energy can be neither created or Energy can be neither created or

destroyed in ordinary changes (not destroyed in ordinary changes (not nuclear), it can only change form.nuclear), it can only change form.

Its not just a good idea, its the Its not just a good idea, its the lawlaw..

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What about nuclear?What about nuclear? E = mcE = mc22 energy = mass x (speed of light)energy = mass x (speed of light)22 speed of light = 3 x 10speed of light = 3 x 1088 A little mass can make a lot of energyA little mass can make a lot of energy Law of Conservation of Mass - EnergyLaw of Conservation of Mass - Energy

the total of the mass and energy the total of the mass and energy remains the same in any changeremains the same in any change