Kinetic theory of matter, states of matter, temperature and thermal expansion.

What do you smell?

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ICE CUBE

Why do you smell the chocolate?

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CScandium

12

52

TeTellerium

128

57

LaLanthanum

139

67

HoHolmium

165

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CoCobalt

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What happens if we heat an ice cube in an empty beaker?If I continue to heat the liquid what happens?

The water turns into a gas (evaporation) and leaves the container.

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Chocolate

Chocolate particles evaporate and diffuse throughout the room, some of which reach your nose.

So when you smell something, those are the particles of that object traveling through the

air and making physical contact with your nose, and

that includes poop and farts.

The Kinetic Theory of Matter says that the particles that were in

someone's butt end up in your nose! YAY SCIENCE!!!

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What Happens if I add a drop of food coloring to a glass of hot and cold water?

Hot Water Cold Water

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KINETIC THEORY OF MATTER• All matter is made up of tiny little

particles and those particles are always randomly moving.

• Temperature is related to the speed of the particles.– Higher temperature = faster

moving and more energy.– Lower temperature = slower

moving and less energy.

• ↑ Speed = ↑ Temperature

• ↓ Speed = ↓ Temperature

https://phet.colorado.edu/en/simulation/states-of-matter-basics

Three States of Matter

Macroscopic Definitions• Gas: Has no definite shape or volume, easily compressible, Fills its container• Liquid: Constant volume, no definite shape, Takes shape of container,

slightly compressible• Solid : Definite volume and shape, rigid and difficult to compress

Microscopic Definitions• Gas: particles are far apart and move rapidly, frequently colliding with other

molecules• Liquid: particles are packed closely together and slide past one another. No

orderly arrangement.• Solid : The particles are rigidly held in place and vibrate. Orderly

arrangement.

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SOLID LIQUID GAS

Shape

Volume

Particle Motion

Arrangement

Picture

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SOLID LIQUID GAS

Shape

Volume

Particle Motion

Arrangement

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SOLID LIQUID GAS

Shape Rigid with a definite or Fixed Shape.

Takes the shape of its container Fills a container

Volume

Particle Motion

Arrangement

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SOLID LIQUID GAS

Shape Rigid with a definite or Fixed Shape.

Takes the shape of its container Fills a container

Volume Definite Volume. Not compressible.

Definite volume. Slightly compressible.

Indefinite volume. Easily compressible

(e.g. a balloon)

Particle Motion

Arrangement

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SOLID LIQUID GAS

Shape Rigid with a definite or Fixed Shape.

Takes the shape of its container Fills a container

Volume Definite Volume. Not compressible.

Definite volume. Slightly compressible.

Indefinite volume. Easily compressible

(e.g. a balloon)

Particle MotionParticles Vibrate but are generally locked

into place.

Particles slide past one another (liquids can

flow)Move rapidly with very high energy.

Arrangement

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SOLID LIQUID GAS

Shape Rigid with a definite or Fixed Shape.

Takes the shape of its container Fills a container

Volume Definite Volume. Not compressible.

Definite volume. Slightly compressible.

Indefinite volume. Easily compressible

(e.g. a balloon)

Particle MotionParticles Vibrate but are generally locked

into place.

Particles slide past one another (liquids can

flow)Move rapidly with very high energy.

ArrangementVery close together in

an orderly arrangement

Close together but not locked into an orderly

arrangement.Particles are very far

apart.

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Let’s Model Particle Motion

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Water is cramped as a solid.

Water is lonely as a gas.

Water parties/mingles as a liquid.

Life as a water molecule!

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SOLID

LIQUID

GAS

MEL

TING

FREE

ZING

EVAPORATION

CONDENSATION

SUBLIMATION

DEPOSITION

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Sublimation: Dry Ice or Carbon Dioxide (CO2) turns directly into gas.

Deposition. precipitation forms in clouds. Frost on grass.

Condensation: bathroom mirror, outside of a drink with ice.

Evaporation: liquid to gas, steam sweating is a cooling process.

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Phase Change of Water Lab

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THERMAL EXPANSION

Erlenmeyer Flask Balloon

What Happens if I put a balloon over an Erlenmeyer Flask and put it on a hot plate/burner? Why?

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Volume and Temperature

• When you heat a substance the particles move faster and the amount of space they take up increases.

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Thermal Expansion

Heating a metal rod causes it to grow longer! The whole will get bigger

if the metal is heated.

DENSITY CHANGES WITH TEMPERATURE

• If a solid object has a mass of 24g and a volume of 12cm3, what is its density and what will happen if it is heated?

• If the object expands to a volume of 16cm3 while being heated, what is its mass new density?

Solid Block

Heat

The Solid Expands

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Power lines and CarsOn hot days metal expands and power lines sag more than on cold days when they are tighter.

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Axe-Fire Demo• Density Decreases as

Temperature Increases

• Density Increases as Temperature Decreases

• Substances Expand when Heated

• Substances Contract when Cooled

T↑ V↑ D↓ T↓ V↓ D↑

Hot Air Balloon Flight TimeGroup Flight Time (s) Group Flight Time (s)

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