Unit 4Unit 4

States of MatterStates of Matter

Key VocabularyKey Vocabulary

MatterMatter SolidSolid LiquidLiquid ViscosityViscosity GasGas Surface tensionSurface tension Thermal energyThermal energy TemperatureTemperature heatheat

MeltingMelting FreezingFreezing VaporizationVaporization CondensationCondensation PressurePressure Buoyant forceBuoyant force Archimedes’ PrincipleArchimedes’ Principle DensityDensity Pascal’s principlePascal’s principle

FoldableFoldable

Pyramid FoldPyramid FoldSide 1Side 1

SolidSolidSide 2Side 2

LiquidLiquidSide 3Side 3

GasGas

What is matter?What is matter?

Anything that has mass and takes up Anything that has mass and takes up spacespace

Give me some examples of matterGive me some examples of matter

States of MatterStates of Matter

3 common states3 common statesSolid, Liquid, GasSolid, Liquid, Gas

2 rare states2 rare statesBose-Einstein CondensateBose-Einstein Condensate

The state of matter that occurs when temperature The state of matter that occurs when temperature approaches absolute zeroapproaches absolute zero

Molecular motion stopsMolecular motion stopsPlasma- found in stars, lightning, and neon lightsPlasma- found in stars, lightning, and neon lights

Most Common in the universe, but uncommon on earthMost Common in the universe, but uncommon on earth

SolidsSolids Matter with a definite shape and volumeMatter with a definite shape and volume Particles are moving in vibration patterns that Particles are moving in vibration patterns that

are not seen by the naked eyeare not seen by the naked eye Amorphous SolidsAmorphous Solids

Have no definite crystal structureHave no definite crystal structure Examples: rubber, plastic, glassExamples: rubber, plastic, glass

Crystalline SolidsCrystalline Solids Particles arranged in repeated 3-D structures called Particles arranged in repeated 3-D structures called

crystalscrystals Examples: Sodium Chloride (cube), diamond Examples: Sodium Chloride (cube), diamond

(pyramidal) (pyramidal) Other examples: Sugars, sand, snowOther examples: Sugars, sand, snow

ConnectionConnection

Amorphous solids are like lemons in a Amorphous solids are like lemons in a bowlbowl

Crystalline solids are like eggs in a cartonCrystalline solids are like eggs in a carton

What is a Liquid?What is a Liquid?

Has a definite volume, but no definite Has a definite volume, but no definite shapeshape

Takes the shape of any container it is Takes the shape of any container it is poured intopoured into

Particles move freely and allow shape Particles move freely and allow shape changeschanges

ViscosityViscosity

A liquid’s resistance to flowA liquid’s resistance to flowHigh viscosity means that the liquid is very High viscosity means that the liquid is very

thick and does not run wellthick and does not run wellExample: molassesExample: molasses

Low viscosity means that the liquid pours Low viscosity means that the liquid pours easilyeasilyExample: waterExample: water

GasesGases

Matter that does not have a definite shape Matter that does not have a definite shape or volumeor volume

Particles are farther apart than in any Particles are farther apart than in any other common stateother common state

Can be expanded or compressedCan be expanded or compressedDecreasing the volume (compressing) Decreasing the volume (compressing)

moves the molecules closer togethermoves the molecules closer together

SPECIAL PROPERTIES OF SPECIAL PROPERTIES OF GASES GASES

The Nature of GasesThe Nature of Gases

Gas Particles can be monatomic (Ne), Gas Particles can be monatomic (Ne), diatomic (Ndiatomic (N22), or polyatomic (CH), or polyatomic (CH44))

All gases have these characteristicsAll gases have these characteristicsMassMassCompressibleCompressibleFill containersFill containersThey diffuseThey diffuseExert pressureExert pressure

Amount of pressure is dependent on temperatureAmount of pressure is dependent on temperature

Kinetic Molecular TheoryKinetic Molecular Theory

Used to explain the behaviors and Used to explain the behaviors and characteristics of gasescharacteristics of gases Kinetic = motion, Molecular = particlesKinetic = motion, Molecular = particles

States that all gas particles are in constant and States that all gas particles are in constant and random motionrandom motion

3 basic assumptions of the law3 basic assumptions of the law Gas is composed of small particles, but mostly empty Gas is composed of small particles, but mostly empty

spacespace The gas particles are in constant random motionThe gas particles are in constant random motion During molecular collisions, no energy is lostDuring molecular collisions, no energy is lost

Gasses are SqueezableGasses are Squeezable

If you squeeze or If you squeeze or compress a gas, its compress a gas, its volume can be volume can be reduced considerablyreduced considerably

A gases’ low density A gases’ low density allows for lost of open allows for lost of open space to be space to be condensedcondensed

The Popcorn Torture MethodThe Popcorn Torture Method

If I opened up a bag If I opened up a bag of popcorn in the front of popcorn in the front of the classroom, the of the classroom, the smell would reach the smell would reach the back very quicklyback very quickly This is because the This is because the

high energy of the high energy of the smell/gas allows it to smell/gas allows it to travel or diffuse quicklytravel or diffuse quickly

Again, the empty space Again, the empty space of a gas allows for this of a gas allows for this movement of molecules movement of molecules past one another until past one another until they fill the spacethey fill the space

Not all gases diffuse at Not all gases diffuse at the same rate, this the same rate, this depends ondepends on Size of the moleculeSize of the molecule Energy in the gasEnergy in the gas ConcentrationConcentration

Gas PressureGas Pressure

Gas Particles exert pressure by colliding Gas Particles exert pressure by colliding with objects in their pathwith objects in their path

The sum of all The sum of all

collisions makes upcollisions makes up

all the pressure the all the pressure the

gas exertsgas exerts

PressurePressure

Pressure is defined as a force per unit Pressure is defined as a force per unit areaareaP = F/AP = F/A

It’s Gettin’ Hot in Here…It’s Gettin’ Hot in Here…

The higher the temperature of a gas, the The higher the temperature of a gas, the higher the pressure the gas exertshigher the pressure the gas exerts

The lower the temperature, the lower the The lower the temperature, the lower the pressurepressure

What kind of relationship is this?What kind of relationship is this?

A Little Logic…A Little Logic…

Since temperature is defined as the Since temperature is defined as the average kinetic energy of an objectaverage kinetic energy of an objectThe higher the temperature, the more energyThe higher the temperature, the more energyThe more energy, the more impacts of gas The more energy, the more impacts of gas

moleculesmoleculesThe more impacts/collisions of gas molecules, The more impacts/collisions of gas molecules,

the more pressure is exertedthe more pressure is exerted

Gas VariablesGas Variables

In order to describe a gas sample, you In order to describe a gas sample, you must be aware of 4 valuesmust be aware of 4 valuesAmount of GasAmount of GasVolumeVolumeTemperatureTemperaturePressurePressure

The Amount of a GasThe Amount of a Gas

Express variably as (n), meaning the Express variably as (n), meaning the number of moles presentnumber of moles present

A mole of gas is 6.02 x 10A mole of gas is 6.02 x 102323 molecules moleculesTo convert mass to moles, you just divide To convert mass to moles, you just divide

by the molar mass of the gasby the molar mass of the gas

Volume of GasVolume of Gas

Represented variably as (V), and is Represented variably as (V), and is measured in liters (L)measured in liters (L)

There might be problems that call for cubic There might be problems that call for cubic meters…know this ratiometers…know this ratio1000 L = 1 m1000 L = 1 m33

Temperature of GasesTemperature of Gases

The temperature of a gas is represented The temperature of a gas is represented variably as (T) and is measured in Kelvin variably as (T) and is measured in Kelvin (K)(K)

To convert from Celsius to Kelvin, simply To convert from Celsius to Kelvin, simply add 273 to your Celsius measurementadd 273 to your Celsius measurement

Pressure of a GasPressure of a Gas

The pressure of a gas is the force exerted The pressure of a gas is the force exerted on the wall of the container the gas is inon the wall of the container the gas is in

It is represented variably as (P) and is It is represented variably as (P) and is measured in three unitsmeasured in three unitsAtmospheres (atm)Atmospheres (atm)Millimeters of Mercury (mmHg)Millimeters of Mercury (mmHg)Kilopascals (KPa)Kilopascals (KPa)

STPSTP

Standard Temperature and PressureStandard Temperature and PressureTemperature = 0Temperature = 0C or 273KC or 273KPresure = 1 atm, 760 mmHg, or 101.3 KPaPresure = 1 atm, 760 mmHg, or 101.3 KPa

Gas LawsGas Laws

We will discuss a few gas laws…you need We will discuss a few gas laws…you need to know them, and be able to calculate to know them, and be able to calculate with themwith themBoyle’s LawBoyle’s LawCharles’s LawCharles’s LawLussac’s LawLussac’s Law

P1V1 = P2V2P1V1 = P2V2

V1 V2

T1 T2

=P1 P2

T1 T2

=

ExamplesExamples

A gas has a volume of 3.0L at 2atm. What is its A gas has a volume of 3.0L at 2atm. What is its volume at 4 atm?volume at 4 atm? Answer: 1.5 LAnswer: 1.5 L

A gas has a volume of 3.0L at 127A gas has a volume of 3.0L at 127C, what is its C, what is its volume at 227volume at 227C? Be sure to convert your C? Be sure to convert your temperatures to Kelvin.temperatures to Kelvin. Answer: 3.8 LAnswer: 3.8 L

A gas has a pressure of 3.0 atm at 127A gas has a pressure of 3.0 atm at 127C. What is C. What is the pressure at 227the pressure at 227C? Be sure to convert your C? Be sure to convert your temperatures to Kelvin.temperatures to Kelvin. Answer: 3.8 atmAnswer: 3.8 atm

What is energy?What is energy?

The ability to do work or make a changeThe ability to do work or make a changeWe will focus on the ability to make a change We will focus on the ability to make a change

nownowAbility to do work comes after the holidaysAbility to do work comes after the holidays

The energy associated with motion is The energy associated with motion is called called kinetic energykinetic energy

The chance that an object might exert The chance that an object might exert energy is energy is potential energypotential energy

Thermal EnergyThermal Energy

The total potential The total potential and kinetic energyand kinetic energy

Depends on the Depends on the amount of energy in a amount of energy in a substance as well as substance as well as how much of a how much of a substance is presentsubstance is present

Temperature Temperature

The average kinetic The average kinetic energy of a substanceenergy of a substance

What is the difference What is the difference between temperature between temperature and thermal energy?and thermal energy?

HeatHeat

The movement of thermal energy from an The movement of thermal energy from an object with more kinetic energy to an object with more kinetic energy to an object with less kinetic energyobject with less kinetic energy

When a substance gains heat, it gets When a substance gains heat, it gets warmerwarmer

When a substance is cooled, it looses heatWhen a substance is cooled, it looses heatWhat happens to the particles when they are What happens to the particles when they are

cooled?cooled?

Specific HeatSpecific Heat

The amount of energy The amount of energy required to raise the required to raise the temperature of 1g of a temperature of 1g of a substance by 1 substance by 1 degree Celsiusdegree Celsius

Surface TensionSurface Tension

The uneven forces acting on the surface of The uneven forces acting on the surface of a liquida liquid

Cause the liquid to act as though there is a Cause the liquid to act as though there is a thin film across the surfacethin film across the surface

This unseen force allows bugs to float on This unseen force allows bugs to float on the surface of a liquidthe surface of a liquid

Believe it or not, you can actually float a Believe it or not, you can actually float a needle on water due to surface tensionneedle on water due to surface tension

Surface Tension LabSurface Tension Lab

Question: Can you place more drops of water on Question: Can you place more drops of water on the surface of a penny than what will simply fit the surface of a penny than what will simply fit on the face of the penny?on the face of the penny?

Hypothesis: If…Then…BecauseHypothesis: If…Then…Because 1 drop at a time place water onto the surface of 1 drop at a time place water onto the surface of

a pennya penny When the surface tension breaks, record the When the surface tension breaks, record the

number of drops in the data section of your number of drops in the data section of your science journalscience journal

Repeat 3 times for accuracyRepeat 3 times for accuracy

MeltingMelting

When an object absorbs When an object absorbs thermal energythermal energy

The increase in thermal The increase in thermal energy causes the energy causes the substance to change from substance to change from solid to liquidsolid to liquid

Amorphous solids do not Amorphous solids do not change like other solidschange like other solids They simply get softer and They simply get softer and

moldablemoldable See figure 10 on page 109See figure 10 on page 109

FreezingFreezing

When a substance When a substance looses thermal energy looses thermal energy

The substance The substance changes from liquid to changes from liquid to solidsolid

The temperature at The temperature at which a substance which a substance freezes is known as freezes is known as freezing pointfreezing point

VaporizationVaporization

When a liquid gains thermal energyWhen a liquid gains thermal energyChanges from a liquid to a gasChanges from a liquid to a gasExample: Water boiling into vaporExample: Water boiling into vapor2 types of vaporization2 types of vaporization

Boiling- air bubbles form within the liquid and Boiling- air bubbles form within the liquid and rise to the surfacerise to the surface

Evaporation- water at the surface vaporizes, Evaporation- water at the surface vaporizes, occurs at temperatures below the boiling pointoccurs at temperatures below the boiling point

Vaporization DemoVaporization Demo

I will place one drop of rubbing alcohol on I will place one drop of rubbing alcohol on the back of your handthe back of your hand

In your science journal, record your In your science journal, record your observations for the next 2 minutesobservations for the next 2 minutes

What happened?What happened?

CondensationCondensation

Decrease in thermal Decrease in thermal energy rearranges the energy rearranges the pattern of a gaspattern of a gas

Causes the gas to Causes the gas to turn into liquidturn into liquid

SublimationSublimation

Change from solid form to Change from solid form to a gas state without ever a gas state without ever becoming a liquidbecoming a liquid

Example: Example: At room temperature At room temperature

carbon dioxide is a gascarbon dioxide is a gas Dry Ice is the solid form of Dry Ice is the solid form of

carbon dioxidecarbon dioxide At room temperature, dry At room temperature, dry

ice instantly turns into a ice instantly turns into a gasgas

PressurePressure

Equal to the force exerted on an object Equal to the force exerted on an object divided by the area over which the force is divided by the area over which the force is exertedexerted

Measured in SI Unit:Measured in SI Unit:Force is measured in Newtons (N)Force is measured in Newtons (N)Area is measured in square meters (mArea is measured in square meters (m22))Therefore pressure is N/mTherefore pressure is N/m22 or a unit called the or a unit called the

Pascal (Pa)Pascal (Pa)

Atmospheric PressureAtmospheric Pressure

The air around you presses on your with a great The air around you presses on your with a great force, you are just used to the pressure so you force, you are just used to the pressure so you don’t feel itdon’t feel it

Atmospheric Pressure on earth is 101.3Pa at Atmospheric Pressure on earth is 101.3Pa at sea levelsea level This is equal to 101,000 N This is equal to 101,000 N

Air pressure enables you to drink from a strawAir pressure enables you to drink from a straw Sucking on the straw eliminates the air in the strawSucking on the straw eliminates the air in the straw The air pressure then pushes the liquid up the straw The air pressure then pushes the liquid up the straw

where there is no longer air pressure pushing where there is no longer air pressure pushing downwarddownward

Using a StrawUsing a Straw

Why don’t you feel the pressure?Why don’t you feel the pressure?

The atmosphere pushes with equal force The atmosphere pushes with equal force on the outside of your body as the liquid in on the outside of your body as the liquid in your body pushes outwardyour body pushes outward

As altitude increases, air pressure As altitude increases, air pressure decreasesdecreasesWhen you rise in an airplane or go up a When you rise in an airplane or go up a

mountain your ears pop. Why?mountain your ears pop. Why?

Buoyant ForceBuoyant Force

An upward force that presses against an An upward force that presses against an object being pushed downward by air object being pushed downward by air pressure and weightpressure and weight

If the buoyant force is equal to the If the buoyant force is equal to the combined forces, the object will floatcombined forces, the object will float

Archimedes’ Principle- the buoyant force Archimedes’ Principle- the buoyant force of an object is equal to the weight of the of an object is equal to the weight of the fluid displaced by the objectfluid displaced by the object

DensityDensity

The density of an object is crucial as to whether The density of an object is crucial as to whether it will floatit will float

Density is mass divided by the volumeDensity is mass divided by the volume An object that is less dense than the fluid will An object that is less dense than the fluid will

floatfloat An object that is more dense than the fluid will An object that is more dense than the fluid will

sinksink An object that is equally as dense as the fluid An object that is equally as dense as the fluid

will neither sink nor float, but remain in the same will neither sink nor float, but remain in the same position in the waterposition in the water

So how do things float?So how do things float?

If density determines the buoyancy of an If density determines the buoyancy of an object, what two factors must be object, what two factors must be considered to make an object float?considered to make an object float?

How do you need to modify these factors How do you need to modify these factors to make an object float?to make an object float?

Effects of Volume and TemperatureEffects of Volume and Temperature

As volume decreases, pressure increasesAs volume decreases, pressure increases As Temperature increases, pressure increases As Temperature increases, pressure increases

alsoalso Bernoulli’s Principle Demo- observe and record Bernoulli’s Principle Demo- observe and record

in your science journalin your science journal What will happen when I place the ping-pong ball on What will happen when I place the ping-pong ball on

the air current?the air current? What will happen if I tilt the air current?What will happen if I tilt the air current? What will happen if I decrease the air pressure?What will happen if I decrease the air pressure?

Chapter Experiment: Build a BoatChapter Experiment: Build a Boat

Get into your science teamsGet into your science teamsQuestion: How does the volume of water Question: How does the volume of water

displaced by a ship relate to the mass of displaced by a ship relate to the mass of cargo a ship can carry? Can you create a cargo a ship can carry? Can you create a ship that can float on water and carry ship that can float on water and carry cargo?cargo?

Hypothesis: If…then…becauseHypothesis: If…then…becauseProcedures: Write your own procedures Procedures: Write your own procedures

for this labfor this lab

Build-A-Boat ConclusionsBuild-A-Boat Conclusions

A ship can only carry a certain amount of A ship can only carry a certain amount of cargo safelycargo safely

It can carry less high-density cargo than It can carry less high-density cargo than high-density cargohigh-density cargo