The Kinetic Theory of The Kinetic Theory of MatterMatter

The TheoryThe Theory

1.1. Matter is composed of particles that are Matter is composed of particles that are in constant motionin constant motion

Is there ever a time when there Is there ever a time when there is NO motion?is NO motion?

This is called absolute zero and is what This is called absolute zero and is what the Kelvin temperature scale is based onthe Kelvin temperature scale is based on

The point at which all motion ceases is The point at which all motion ceases is absolute zero on the Kelvin scale… This is absolute zero on the Kelvin scale… This is only theoreticalonly theoretical

To convert from Kelvin to Celsius just To convert from Kelvin to Celsius just subtract 273.15, and add to go from subtract 273.15, and add to go from Celsius to KelvinCelsius to Kelvin

Kelvin Vs CelsiusKelvin Vs Celsius

Remember!!!Remember!!!

Heat is Molecular motion… Not Heat is Molecular motion… Not temperature.temperature.

Temperature is a measure of the effect of Temperature is a measure of the effect of heat: The kinetic energy of a systemheat: The kinetic energy of a system

Why do we have this Theory?Why do we have this Theory?1.1. Helps us predictHelps us predict

1.1. Heat transferHeat transfer

2.2. PressurePressure

3.3. TemperatureTemperature

4.4. Properties of matterProperties of matter

MotionMotion

1.1. These particles have spaces in between These particles have spaces in between themthem

1.1. They move around in these spacesThey move around in these spaces

What kinds of motion are there?What kinds of motion are there?

Vibrational:Vibrational: Rotational:Rotational: Translational:Translational:

PlasmaPlasma

GasesGases

1.1. In gases, the spaces are far apart: In gases, the spaces are far apart: Vibrational, Rotational TranslationalVibrational, Rotational Translational

LiquidsLiquids

1.1. In liquids, the spaces are smaller: In liquids, the spaces are smaller: Vibrational, RotationalVibrational, Rotational

1.1. Now there is a fixed volumeNow there is a fixed volume

SolidsSolids

1.1. Even in solids, the particles are moving: Even in solids, the particles are moving: VibrationalVibrational

1.1. Now there is a fixed shape, tooNow there is a fixed shape, too

ResonanceResonance

Everything that vibrates has a specific Everything that vibrates has a specific frequency of resonance very specific to frequency of resonance very specific to it… JUST LIKE ENERGY doesit… JUST LIKE ENERGY does

Effects of EnergyEffects of Energy

1.1. If heat is increased, the particles move If heat is increased, the particles move fasterfaster

1.1. And visa versaAnd visa versa

Enthalpy, EntropyEnthalpy, Entropy

Enthalpy: Quantity of heat energyEnthalpy: Quantity of heat energy Entropy: Degree of dosorderEntropy: Degree of dosorder

As Enthalpy increases, entropy also As Enthalpy increases, entropy also increases, except in natureincreases, except in nature

In NatureIn Nature

As enthalpy is released (exothermic), As enthalpy is released (exothermic), entropy increases because it takes energy entropy increases because it takes energy to hold bonds in nature togetherto hold bonds in nature together

As enthalpy is required (endothermic) As enthalpy is required (endothermic) entropy decreases because natural entropy decreases because natural systems require energy to bondsystems require energy to bond

BasicallyBasically

1.1. The higher the temperature, the faster The higher the temperature, the faster the particles movethe particles move

Solids-Solids-

Liquids-Liquids-

How these Theories ConnectHow these Theories Connect

1.1. The more thermal energy, the faster the The more thermal energy, the faster the particles moveparticles move

Phase changesPhase changes

Melting (fusion): solidMelting (fusion): solid liquid liquid Boiling (vaporization): liquidBoiling (vaporization): liquid gas gas Condensation: GasCondensation: Gas liquid liquid Freezing (solidification): liquidFreezing (solidification): liquid solid solid Sublimation: Solid Sublimation: Solid gas gas Deposition: gasDeposition: gas solid solid Each of these occur at specific temperatures Each of these occur at specific temperatures

and pressures based on the substanceand pressures based on the substance

Vapo(u)r pressureVapo(u)r pressure

The pressure exerted by a vapor in The pressure exerted by a vapor in equilibrium with its solid or liquid phaseequilibrium with its solid or liquid phase

Enclosed system usually: even our Enclosed system usually: even our atmosphereatmosphere

What is gas pressureWhat is gas pressure

The smashing, bashing, and crashing of The smashing, bashing, and crashing of air molecules:air molecules:

Check it out

Water vapor pressureWater vapor pressure

Phase diagramPhase diagram

Substances make transitions from one Substances make transitions from one phase to another based on temperature phase to another based on temperature and vapor pressureand vapor pressure

Graph plotting the phase changes at a Graph plotting the phase changes at a specific combination of vapor pressure specific combination of vapor pressure and temperature: Phase diagramand temperature: Phase diagram