c16 solids, liquids,-and_gases

Solids, Liquids, and GasesSolids, Liquids, and GasesChapter 16Chapter 16

Section 1 Kinetic TheorySection 1 Kinetic Theory

Solids, Liquids, and GasesSolids, Liquids, and Gases• Section 1 Kinetic theory slides 3-47Section 1 Kinetic theory slides 3-47• Section 2 Properties of Fluids Section 2 Properties of Fluids

slides 50-64• Section 3 Behavior of Gases Section 3 Behavior of Gases

slides 65-80

1 Kinetic Theory of Matter1 Kinetic Theory of Matter• Kinetic theoryKinetic theory• How particles move in the four states How particles move in the four states

of matterof matter• How particles behave at the melting How particles behave at the melting

point and boiling pointspoint and boiling points

Kinetic TheoryKinetic Theory• Explains how particles of matter Explains how particles of matter

behave using three basic behave using three basic assumptions:assumptions:– 1) All matter is composed of small 1) All matter is composed of small

particles- atoms, molecules and ions.particles- atoms, molecules and ions.


behave using three basic behave using three basic assumptions:assumptions:– 1) All matter is composed of small 1) All matter is composed of small

particles- atoms, molecules and ions.particles- atoms, molecules and ions.– 2) These particles are in constant 2) These particles are in constant

motion. The motion has no pattern.motion. The motion has no pattern.


behave using three basic assumptions:behave using three basic assumptions:– 1) All matter is composed of small 1) All matter is composed of small

particles- atoms, molecules and ions.particles- atoms, molecules and ions.– 2) These particles are in constant motion. 2) These particles are in constant motion.

The motion has no pattern.The motion has no pattern.– 3) These particles are colliding or 3) These particles are colliding or

crashing into each other and into the walls crashing into each other and into the walls of the container.of the container.

Thermal EnergyThermal Energy• Thermal energy is the total energy of Thermal energy is the total energy of

the particles in a material including the particles in a material including both potential and kinetic. both potential and kinetic.

• When the temperature is lowered, its When the temperature is lowered, its particles will have less TE and will particles will have less TE and will vibrate more slowly.vibrate more slowly.

Average Kinetic EnergyAverage Kinetic Energy• Temperature is the Temperature is the

average KE of average KE of particles in a particles in a substance.substance.

• The molecules in a The molecules in a solid randomly solid randomly vibrate with vibrate with temperature a temperature a measure of their measure of their average kinetic average kinetic energy.energy.

How do solids become How do solids become liquids?liquids?• Melting point Melting point is the temperature at is the temperature at

which a solid begins to turn into a which a solid begins to turn into a liquid.liquid.


which a solid begins to turn into a which a solid begins to turn into a liquid.liquid.

• Energy is needed for the particles in Energy is needed for the particles in a solid to slip out of their ordered a solid to slip out of their ordered arrangement.arrangement.


which a solid begins to turn into a liquid.which a solid begins to turn into a liquid.• Energy is needed for the particles in a Energy is needed for the particles in a

solid to slip out of their ordered solid to slip out of their ordered arrangement.arrangement.

• Heat of fusionHeat of fusion is the amount of energy is the amount of energy needed to change a substance from a needed to change a substance from a solid to a liquid at its melting point.solid to a liquid at its melting point.

Why do liquids flow?Why do liquids flow?• Particles in liquids have more KE Particles in liquids have more KE

allowing them to overcome their allowing them to overcome their attraction and slide past each other attraction and slide past each other more readily.more readily.

• This is why liquids flow and take the This is why liquids flow and take the shape of their container; however, shape of their container; however, they still cling together and have a they still cling together and have a definite volume. definite volume.

What is a gas state?What is a gas state?• Gas particles have enough KE to Gas particles have enough KE to

overcome the attractions among overcome the attractions among them so that they have no fixed them so that they have no fixed volume or shape. volume or shape.

What is a gas state?What is a gas state?• Gas particles have enough KE to Gas particles have enough KE to

overcome the attractions among overcome the attractions among them so that they have no fixed them so that they have no fixed volume or shape. volume or shape.

• They can spread far apart or move They can spread far apart or move close together to fill a container.close together to fill a container.

What is a gas state?What is a gas state?• Gas particles have enough KE to overcome Gas particles have enough KE to overcome

the attractions among them so that they the attractions among them so that they have no fixed volume or shape. have no fixed volume or shape.

• They can spread far apart or move close They can spread far apart or move close together to fill a container.together to fill a container.

• If particles in a liquid move fast enough If particles in a liquid move fast enough they can enter the gas state in a process they can enter the gas state in a process called vaporization by evaporation or called vaporization by evaporation or boiling.boiling.

How do liquids evaporate?How do liquids evaporate?• Evaporation is vaporization that Evaporation is vaporization that

occurs at the surface of a liquid.occurs at the surface of a liquid.• It can occur below the liquid’s boiling It can occur below the liquid’s boiling

point if particles at the surface have point if particles at the surface have enough KE to escape liquid’s enough KE to escape liquid’s attractive force.attractive force.

How does boiling vaporize How does boiling vaporize liquids?liquids?• Boiling occurs at a specific Boiling occurs at a specific

temperature which depends on the temperature which depends on the pressure on the surface of the liquid. pressure on the surface of the liquid.

How does boiling vaporize How does boiling vaporize liquids?liquids?• Boiling occurs at a specific Boiling occurs at a specific

temperature which depends on the temperature which depends on the pressure on the surface of the liquid. pressure on the surface of the liquid.

• Air exerts pressure on the surface of Air exerts pressure on the surface of the liquid which keeps particles from the liquid which keeps particles from escaping the liquid.escaping the liquid.

How does boiling vaporize How does boiling vaporize liquids?liquids?• The The boiling point boiling point of a liquid is the of a liquid is the

temperature at which the pressure of temperature at which the pressure of the vapor in the liquid is equal to the the vapor in the liquid is equal to the external pressure on the surface of external pressure on the surface of the liquid.the liquid.

How does boiling vaporize How does boiling vaporize liquids?liquids?• The The boiling point boiling point of a liquid is the of a liquid is the

temperature at which the pressure of temperature at which the pressure of the vapor in the liquid is equal to the the vapor in the liquid is equal to the external pressure on the surface of external pressure on the surface of the liquid.the liquid.

• Particles need energy to overcome Particles need energy to overcome the force of pressure.the force of pressure.

How does boiling vaporize How does boiling vaporize liquids?liquids?• Heat of vaporizationHeat of vaporization is the amount is the amount

of energy needed for the liquid at its of energy needed for the liquid at its boiling point to become a gas.boiling point to become a gas.

Why do gases fill their Why do gases fill their containers?containers?• Gas particles move so quickly & are Gas particles move so quickly & are

so far apart that they overcome the so far apart that they overcome the attractive forces among them; attractive forces among them; therefore, therefore, gases do not have a gases do not have a definite shape or a definite volume.definite shape or a definite volume.

Why do gases fill their Why do gases fill their containers?containers?• Gas particles move so quickly & are Gas particles move so quickly & are

so far apart that they overcome the so far apart that they overcome the attractive forces among them; attractive forces among them; therefore, therefore, gases do not have a gases do not have a definite shape or a definite volume.definite shape or a definite volume.

• DiffusionDiffusion is the spreading of is the spreading of particles throughout a given volume particles throughout a given volume until they are evenly distributed.until they are evenly distributed.

What is the heating curve of a What is the heating curve of a liquid?liquid?

What is the heating curve of a What is the heating curve of a liquid?liquid?• The graph slopes The graph slopes

upward when the upward when the KE is rising. KE is rising.

• At B & D the graph At B & D the graph is a horizontal line is a horizontal line showing water showing water temperature does temperature does not change.not change.

What is the heating curve of a What is the heating curve of a liquid?liquid?• At what temp is the At what temp is the

water turning into water turning into a gas?a gas?

What is the heating curve of a What is the heating curve of a liquid?liquid?• At 0At 0°C, ice is melting. °C, ice is melting.

What is the heating curve of a What is the heating curve of a liquid?liquid?• At 0At 0°C, ice is melting. °C, ice is melting. • All of the energy put into ice at this All of the energy put into ice at this

temp is used to overcome the temp is used to overcome the attractive forces among the particles attractive forces among the particles in the solid. in the solid.

What is the heating curve of a What is the heating curve of a liquid?liquid?• At 0At 0°C, ice is melting. °C, ice is melting. • All of the energy put into ice at this All of the energy put into ice at this

temp is used to overcome the temp is used to overcome the attractive forces among the particles attractive forces among the particles in the solid. in the solid.

• After melting, the particles move After melting, the particles move more freely and their temp begins to more freely and their temp begins to rise.rise.

What is the heating curve of a What is the heating curve of a liquid?liquid?• At 100At 100°C, water is boiling or °C, water is boiling or

vaporizing.vaporizing.


vaporizing.vaporizing.• The temperature stays the same The temperature stays the same

again until the attractive forces are again until the attractive forces are overcome.overcome.


vaporizing.vaporizing.• The temperature stays the same The temperature stays the same

again until the attractive forces are again until the attractive forces are overcome.overcome.

• Then energy returns to raising the Then energy returns to raising the temperatures of the particles.temperatures of the particles.

What is the plasma state?What is the plasma state?• Much of the matter in the universe is Much of the matter in the universe is

plasmaplasma, matter made up of , matter made up of positively and negatively charged positively and negatively charged particles with an overall neutral particles with an overall neutral charge.charge.


plasmaplasma, matter made up of , matter made up of positively and negatively charged positively and negatively charged particles with an overall neutral particles with an overall neutral charge.charge.

• The faster they move, the greater The faster they move, the greater the force when they collide causing the force when they collide causing atoms to rip off.atoms to rip off.


plasmaplasma, matter made up of positively and , matter made up of positively and negatively charged particles with an negatively charged particles with an overall neutral charge.overall neutral charge.

• The faster they move, the greater the The faster they move, the greater the force when they collide causing atoms to force when they collide causing atoms to rip off.rip off.

• Ex. Stars, lightning bolts, neon & Ex. Stars, lightning bolts, neon & fluorescent bulbs, and auroras.fluorescent bulbs, and auroras.

Thermal ExpansionThermal Expansion• Thermal expansion Thermal expansion is an increase is an increase

in the size of a substance when the in the size of a substance when the temperature is increased.temperature is increased.

• The kinetic theory explains both The kinetic theory explains both thermal expansion and contraction thermal expansion and contraction that occurs in most solids, liquids and that occurs in most solids, liquids and gases.gases.

How does expansion occur in How does expansion occur in solids?solids?• Expansion joints prevent concrete Expansion joints prevent concrete

cracks when temperatures change.cracks when temperatures change.

How does expansion occur in How does expansion occur in liquids?liquids?

• One example of One example of this occurs in a this occurs in a thermometer.thermometer.

• The addition of The addition of energy makes energy makes particles in the particles in the liquid move farther liquid move farther apart.apart.

How does expansion occur in How does expansion occur in gases?gases?

• An example is a An example is a hot air balloon. hot air balloon. Heating the air Heating the air makes it expand makes it expand and decreases the and decreases the density making the density making the balloon rise.balloon rise.

Why does water behave in Why does water behave in different ways?different ways?

• Water expands Water expands when it freezes due when it freezes due to the negative and to the negative and positive charges on positive charges on it.it.

Why does water behave in Why does water behave in different ways?different ways?• Water expands when it freezes due to Water expands when it freezes due to

the negative and positive charges on the negative and positive charges on it.it.

• Unlike charges attract each other. As Unlike charges attract each other. As the temp drops, the water particles the temp drops, the water particles move closer together lining up so that move closer together lining up so that positive and negative areas are near positive and negative areas are near each other leaving empty spaces in each other leaving empty spaces in the structure.the structure.

Why does water behave in Why does water behave in different ways?different ways?• Water expands when it freezes due to the Water expands when it freezes due to the

negative and positive charges on it.negative and positive charges on it.• Unlike charges attract each other. As the Unlike charges attract each other. As the

temp drops, the water particles move temp drops, the water particles move closer together lining up so that positive closer together lining up so that positive and negative areas are near each other and negative areas are near each other leaving empty spaces in the structure.leaving empty spaces in the structure.

• Solid ice is less dense than liquid water.Solid ice is less dense than liquid water.

Solid or Liquid?Solid or Liquid?• Not all materials have a definite Not all materials have a definite

temperature when they change from temperature when they change from solid to liquid. solid to liquid.

• Some get softer and slowly turn to Some get softer and slowly turn to liquid over a range of temperatures.liquid over a range of temperatures.

Solid or Liquid?Solid or Liquid?• Not all materials have a definite Not all materials have a definite

temperature when they change from temperature when they change from solid to liquid. solid to liquid.

• Some get softer and slowly turn to Some get softer and slowly turn to liquid over a range of temperatures.liquid over a range of temperatures.

• These These amorphousamorphous solids, like glass solids, like glass & plastic, do not have the ordered & plastic, do not have the ordered structure of crystals.structure of crystals.

Solid or a Liquid?Solid or a Liquid?• Liquid crystals start to flow in the Liquid crystals start to flow in the

melting phase, but keep their ordered melting phase, but keep their ordered structure.structure.

• Liquid crystals respond to Liquid crystals respond to temperature changes and electric temperature changes and electric fields.fields.

• LCDs are used in watches and LCDs are used in watches and calculators.calculators.

Solid Liquid Gas

Arrangement:Closely packed together

Arrangement: Arrangement:Overcome attractions

Behavior: Behavior: slip out of arrangement & flow

Behavior:

Solid Liquid Gas

Arrangement:Closely packed together

Arrangement: Cling together with definite volume

Arrangement:Overcome attractions

Behavior: Energy is needed for them to slip out of arrangement

Behavior: slip out of arrangement & flow

Behavior: do not have definite shape or volume

2 Properties of Fluids2 Properties of Fluids• Archimedes’ PrincipleArchimedes’ Principle• Pascal’s PrinciplePascal’s Principle• Bernoulli’s PrincipleBernoulli’s Principle

How do ships float?How do ships float?• Buoyancy Buoyancy is a fluid’s ability to exert is a fluid’s ability to exert

an upward force on an object in it.an upward force on an object in it.

How do ships float?How do ships float?• Buoyancy Buoyancy is a fluid’s ability to exert is a fluid’s ability to exert

an upward force on an object in it.an upward force on an object in it.• Ships float because the force pushing Ships float because the force pushing

up on the ship is greater than the up on the ship is greater than the force of the ship pushing down.force of the ship pushing down.

How do ships float?How do ships float?• Buoyancy Buoyancy is a fluid’s ability to exert an is a fluid’s ability to exert an

upward force on an object in it.upward force on an object in it.• Ships float because the force pushing up Ships float because the force pushing up

on the ship is greater than the force of the on the ship is greater than the force of the ship pushing down.ship pushing down.

• If the buoyant force is equal to the If the buoyant force is equal to the object’s weight, it floats; if the object’s weight, it floats; if the buoyant force is less than the buoyant force is less than the object’s weight, the object sinks.object’s weight, the object sinks.

What is Archimedes’ What is Archimedes’ principle?principle?• The buoyant force on an object is The buoyant force on an object is

equal to the weight of the fluid equal to the weight of the fluid displaced by the object. (displaced displaced by the object. (displaced or “pushed away”)or “pushed away”)

What is Archimedes’ What is Archimedes’ principle?principle?• The buoyant force on an object is The buoyant force on an object is

equal to the weight of the fluid equal to the weight of the fluid displaced by the object. (displaced displaced by the object. (displaced or “pushed away”)or “pushed away”)

• A block of wood sinks until it A block of wood sinks until it displaces enough water to equal its displaces enough water to equal its weight, then it floats.weight, then it floats.

Do equal-sized objects Do equal-sized objects float?float?• Would a steel block the same size as Would a steel block the same size as

the wood block float in water?the wood block float in water?

Do equal-sized objects Do equal-sized objects float?float?• Would a steel block Would a steel block

the same size as the the same size as the wood block float in wood block float in water?water?

• The volume The volume displaced for each displaced for each block is equal; block is equal; however, each block however, each block has a different mass has a different mass & a different density& a different density

•

http://upload.wikimedia.org/wikipedia/en/3/3a/Buoyancy.jpg

What does density have to do What does density have to do with buoyancy?with buoyancy?• If you formed the steel block into the If you formed the steel block into the

shape of a boat filled with air, it will float.shape of a boat filled with air, it will float.• The density of the steel boat with air The density of the steel boat with air

inside is less than the density of the water.inside is less than the density of the water.

Pascal’s PrinciplePascal’s Principle• Pressure Pressure is force exerted per unit is force exerted per unit

area or P= E/A.area or P= E/A.• Blaise Pascal (1623-1662), a French Blaise Pascal (1623-1662), a French

scientist, discovered a useful property scientist, discovered a useful property of fluids.of fluids.

• Pressure applied to a fluid is Pressure applied to a fluid is transmitted or sent throughout the transmitted or sent throughout the fluid. Ex. Squeezing a toothpaste tube.fluid. Ex. Squeezing a toothpaste tube.

How is Pascal’s principle How is Pascal’s principle used?used?• Hydraulic machines Hydraulic machines

move heavy loads move heavy loads using Pascal’s using Pascal’s principle. A fluid-principle. A fluid-filled pipe connects filled pipe connects two cylinders. When two cylinders. When pressure is applied pressure is applied to the smaller one, it to the smaller one, it is transferred to the is transferred to the larger one providing larger one providing more force.more force.

Bernoulli’s PrincipleBernoulli’s Principle• Daniel Bernoulli, a Swiss scientist (1700-Daniel Bernoulli, a Swiss scientist (1700-

1782), discovered that as the velocity of a 1782), discovered that as the velocity of a fluid increases, the pressure exerted by fluid increases, the pressure exerted by the fluid decreases.the fluid decreases.

Bernoulli’s PrincipleBernoulli’s Principle• Engineers use this principle when Engineers use this principle when

designing aircraft wings and piping designing aircraft wings and piping systems.systems.

Fluid FlowFluid Flow• Another property of a fluid is its Another property of a fluid is its

tendency to flow. tendency to flow. • Viscosity Viscosity , resistance to flow by a , resistance to flow by a

fluid, measures how much force is fluid, measures how much force is needed for one layer of fluid to flow needed for one layer of fluid to flow over another layer.over another layer.

Fluid FlowFluid Flow• Another property of a fluid is its Another property of a fluid is its

tendency to flow. tendency to flow. • Viscosity Viscosity , resistance to flow by a , resistance to flow by a

fluid, measures how much force is fluid, measures how much force is needed for one layer of fluid to flow needed for one layer of fluid to flow over another layer.over another layer.

• Water has a low viscosity, but syrup Water has a low viscosity, but syrup has a high viscosity because it flows has a high viscosity because it flows slowly.slowly.

3 Behavior of Gases3 Behavior of Gases• How a gas exerts pressure on its How a gas exerts pressure on its

containercontainer• How changing pressure, How changing pressure,

temperature, or volume affect a gastemperature, or volume affect a gas

PressurePressure• According to the kinetic theory, gas According to the kinetic theory, gas

particles move constantly bumping into particles move constantly bumping into whatever is in their path.whatever is in their path.

• These collisions result in pressure or These collisions result in pressure or amount of force exerted per unit of amount of force exerted per unit of area.area.

• Formula P = F/AFormula P = F/A• Ex. Balloon, tireEx. Balloon, tire

How is pressure measured?How is pressure measured?• SI Unit for pressure is SI Unit for pressure is pascal (pa) pascal (pa) = =

one Newton per square meter or 1 one Newton per square meter or 1 N/mN/m22. .


one Newton per square meter or 1 one Newton per square meter or 1 N/mN/m22. .

• Because this is very small pressure Because this is very small pressure unit, most pressures are given in unit, most pressures are given in kilopascals or kPa.kilopascals or kPa.


one Newton per square meter or 1 N/mone Newton per square meter or 1 N/m22. . • Because this is very small pressure Because this is very small pressure

unit, most pressures are given in unit, most pressures are given in kilopascals or kPa.kilopascals or kPa.

• Atmospheric pressure at sea level = Atmospheric pressure at sea level = 101.3 kPa or about weight of large truck 101.3 kPa or about weight of large truck /square meter! (decreases with /square meter! (decreases with altitude)altitude)

Boyle’s LawBoyle’s Law• If the container gets smaller, what If the container gets smaller, what

happens to the pressure?happens to the pressure?

Boyle’s LawBoyle’s Law• If the container gets smaller, what If the container gets smaller, what

happens to the pressure?happens to the pressure?• Robert Boyle, British scientist (1627-Robert Boyle, British scientist (1627-

1691) If you decrease volume of a 1691) If you decrease volume of a container of gas & keep the temperature container of gas & keep the temperature the same, the pressure of the gas will the same, the pressure of the gas will increase. If you increase the volume & increase. If you increase the volume & keep temp same, pressure will decrease.keep temp same, pressure will decrease.

Pressure outside an object Pressure outside an object affects volumeaffects volume• Weather balloons Weather balloons

carry instruments carry instruments to high altitudes; to high altitudes; as they rise they as they rise they get bigger due to get bigger due to decrease in decrease in atmospheric atmospheric pressure.pressure.

Using Boyle’s LawUsing Boyle’s Law• The pressure inside an object The pressure inside an object

multiplied by its volume is always multiplied by its volume is always equal to the same number, or a equal to the same number, or a constant, when the temperature stays constant, when the temperature stays the same.the same.

• PP11VV11= constant = P= constant = P22VV22

• If you know three values, you can find If you know three values, you can find the unknown fourth value.the unknown fourth value.

Using Boyle’s LawUsing Boyle’s Law

• Use the equation PUse the equation P11VV11 = P = P22VV2. 2. Assume Assume that Pthat P11= 101 kPa and V= 101 kPa and V11=10.0 L. If =10.0 L. If PP22= 43.0 kPa , what is V= 43.0 kPa , what is V22??

Using Boyle’s LawUsing Boyle’s Law

• Use the equation PUse the equation P11VV11 = P = P22VV2. 2. Assume Assume that Pthat P11= 101 kPa and V= 101 kPa and V11=10.0 L. If =10.0 L. If PP22= 43.0 kPa , what is V= 43.0 kPa , what is V22??

• 101 kPa 101 kPa · 10.0 L = 1010 kPaL · 10.0 L = 1010 kPaL 1010 kPaL/43.0 kPa = 24.5 L 1010 kPaL/43.0 kPa = 24.5 L

The Pressure-Temperature The Pressure-Temperature RelationshipRelationship• Have you ever seen “keep away from Have you ever seen “keep away from

heat” on a spray can? Why?heat” on a spray can? Why?

The Pressure-Temperature The Pressure-Temperature RelationshipRelationship• Have you ever seen “keep away from Have you ever seen “keep away from

heat” on a spray can? Why?heat” on a spray can? Why?• Heat causes the pressure to increase Heat causes the pressure to increase

since the can is rigid & cannot since the can is rigid & cannot increase in size until the pressure is increase in size until the pressure is too much and the can explodes. In too much and the can explodes. In low temps, decrease in pressure may low temps, decrease in pressure may cause the container to buckle.cause the container to buckle.

Charles’s LawCharles’s Law• Jacques Charles, French scientist, Jacques Charles, French scientist,

1746-1823, studied gases.1746-1823, studied gases.• Volume of gas increases with Volume of gas increases with

increasing temperature if pressure increasing temperature if pressure remains the same or volume remains the same or volume decreases as temperature decreases.decreases as temperature decreases.

Charles’s LawCharles’s Law• As gas is heated, its As gas is heated, its

particles move particles move faster & faster & its faster & faster & its temperature temperature increases. Instead increases. Instead of increased of increased pressure the volume pressure the volume increases as it increases as it expands the expands the container.container.

Charles’s LawCharles’s Law• Charles’s Law Charles’s Law

formulaformula• VV11/T/T11= V= V22/T/T2 2 when when

pressure kept pressure kept constantconstant

c16 solids, liquids,-and_gases

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