STATES OF MATTERSTATES OF MATTER:: Kinetic Theory- the tiny particles in all Kinetic Theory- the tiny particles in all

forms of matter are in constant motion.forms of matter are in constant motion. Kinetic Energy: energy of motionKinetic Energy: energy of motion SOLIDS:SOLIDS: The particles in solids: Are packed together (often in an Are packed together (often in an

organized pattern called a crystal lattice)organized pattern called a crystal lattice) Are held together by strong forces Are held together by strong forces

(therefore have high melting points)(therefore have high melting points) Vibrate about fixed pointsVibrate about fixed points

CrystalCrystal

Solid with atoms, ions or molecules Solid with atoms, ions or molecules arranged in an orderly, repeating 3-D arranged in an orderly, repeating 3-D pattern.pattern.

Unit Cell- smallest group of particles within Unit Cell- smallest group of particles within a crystal that retains the shape of the a crystal that retains the shape of the crystalcrystal

Crystals are classified in to 7 systems- Crystals are classified in to 7 systems- most of which are square cubic or most of which are square cubic or rectangular cubic.rectangular cubic.

•Allotropes-Allotropes-

Example: Solid CarbonExample: Solid Carbon GRAPHITE DIAMOND BUCKEY BALLGRAPHITE DIAMOND BUCKEY BALL

Oxygen; OOxygen; O22 gas or O gas or O33 gas (ozone) gas (ozone)

A molecular form of an element that A molecular form of an element that exists in 2 or more different forms in the exists in 2 or more different forms in the

same physical statesame physical state

PENCIL

Widely spaced, linked, hexagon.

Weak bonds - soft

Each CARBON atom is strongly

bonded to 4 other carbons

hard

60 carbons attached

together like a soccer ball.

Really flexible

Carbon AllotropesCarbon Allotropes

So far, it is just of theoretical interest. It is not used in any products or manufacturing processes. One process developed in the Chemistry Division at Argonne National Lab produces smooth thin films of diamond from bucky balls. These films are smoother than those produced by any other method. This some day may be useful in making wear-resistant coatings on things like machine parts.

Amorphous solids Amorphous solids lack an orderly internal structure. Atoms lack an orderly internal structure. Atoms

are randomly arranged.are randomly arranged.

Examples: rubber, asphalt, plasticsExamples: rubber, asphalt, plastics Glasses: Glasses: Amorphous solids; super cooled liquidsAmorphous solids; super cooled liquids Cooled to a rigid state without crystallizing. Cooled to a rigid state without crystallizing.

Does not melt at a definite temperature but Does not melt at a definite temperature but gradually softens. When broken it forms gradually softens. When broken it forms jagged irregular edges.jagged irregular edges.

LiquidsLiquids Most liquids are polar molecular Most liquids are polar molecular

compounds. (polar: to have + and – areas)compounds. (polar: to have + and – areas)

The particles in a liquid:The particles in a liquid: Are packed together (almost as closely as Are packed together (almost as closely as

a solid)a solid)

Are held together by weak attractive Are held together by weak attractive forces*(therefore have low melting points)forces*(therefore have low melting points)

Slide past each other (vibrate and spin in Slide past each other (vibrate and spin in fixed positions.fixed positions.

Intermolecular ForcesIntermolecular Forces

Attractive forces between moleculesAttractive forces between molecules The positve end of one molecule is The positve end of one molecule is

attracted to the negative end of an attracted to the negative end of an adjacent molecule. adjacent molecule.

Weakest: London dispersion forcesWeakest: London dispersion forces Stronger; dipole – dipole interactionsStronger; dipole – dipole interactions Strongest; Hydrogen- bondingStrongest; Hydrogen- bonding

GASES:GASES:Most gases are non-polar molecular Most gases are non-polar molecular compoundscompounds

The particles in gases:The particles in gases: Are very far apart (gases are about 99.99% Are very far apart (gases are about 99.99%

empty spaceempty space Have no attractive forces (therefore have Have no attractive forces (therefore have

extremely low melting points.)extremely low melting points.) Move very rapidly and in constant random Move very rapidly and in constant random

straight line motion.straight line motion. Diffuse from areas of high concentration to areas Diffuse from areas of high concentration to areas

of low concentration (smaller lighter molecules of low concentration (smaller lighter molecules diffuse at a faster rate than larger heavier diffuse at a faster rate than larger heavier molecules)molecules)

Perfectly Elastic CollisionsPerfectly Elastic Collisions

Collisions between gas molecules in which Collisions between gas molecules in which no energy is lostno energy is lost

(energy is transferred from one particle to (energy is transferred from one particle to another)another)

Summation of States of MatterSummation of States of Matter

Solids Liquids GasesAttractive Forces

Forces b/t particles

MolecularPacking

Molecular Motion

characteristics IncompressibleIncompressible

Definite shapeDefinite shape

Definite volumeDefinite volume

Nearly Nearly incompressibleincompressible

Indefinite shapeIndefinite shape

Definite volumeDefinite volume

CompressibleCompressible

Indefinite shapeIndefinite shape

Indefinite volumeIndefinite volume

Very Strong NONE

Bounce off each other

weak

Very tight, close99% empty space

Very far apartClosely packed

Vibrate in placeSlide past each

otherRapid, random straight

line motion

Ave. speed = 1000mph

PlasmaPlasma

1. occurs at extremely high temperatures. 1. occurs at extremely high temperatures. (millions of degrees Celsius) KE becomes great (millions of degrees Celsius) KE becomes great enough to break molecules into atoms.enough to break molecules into atoms.

2. At these temperatures electrons have been 2. At these temperatures electrons have been removed from the gaseous atoms.removed from the gaseous atoms.

3. The resulting fluid of bare nuclei (+ ions) and 3. The resulting fluid of bare nuclei (+ ions) and free electrons is called plasma.free electrons is called plasma.

COLD PLASMA – 50,000K to 1,000,000KCOLD PLASMA – 50,000K to 1,000,000K HOT PLASMA- “stars” 10,000,000 to HOT PLASMA- “stars” 10,000,000 to

1,000,000,000K1,000,000,000K

Bose-Einstein Bose-Einstein A A Bose–Einstein condensate (BEC)Bose–Einstein condensate (BEC) is a is a state of matter of of bosons

confined in an external confined in an external potential and cooled to and cooled to temperatures very very near to near to absolute zero (0 (0 K or -273.15 °C). Under such or -273.15 °C). Under such supercooled conditions, a large fraction of the atoms collapse into the lowest conditions, a large fraction of the atoms collapse into the lowest quantum state of the external potential, at which point quantum of the external potential, at which point quantum effects become apparent on a macroscopic scale.effects become apparent on a macroscopic scale.

This state of matter was first predicted by This state of matter was first predicted by Satyendra Nath Bose in in 1925. Bose submitted a paper to the 1925. Bose submitted a paper to the Zeitschrift für PhysikZeitschrift für Physik but was but was turned down by the peer review. Bose then took his work to turned down by the peer review. Bose then took his work to Einstein who recognized its merit and had it published under the Einstein who recognized its merit and had it published under the names Bose and Einstein hence the acronymn.names Bose and Einstein hence the acronymn.

Seventy years later, the first such condensate was produced by Seventy years later, the first such condensate was produced by Eric Cornell and and Carl Wieman in 1995 at the in 1995 at the University of Colorado at Boulder NIST--JILA lab, using a gas of lab, using a gas of rubidium atoms cooled to 170 atoms cooled to 170 nanokelvin (nK) (nK)[1] (0.000000170 (0.000000170 K or -273.14999983 °or -273.14999983 °C). ). Eric Cornell, , Carl Wieman and and Wolfgang Ketterle at at MIT were awarded the 2001 were awarded the 2001 Nobel Prize in Physics in Stockholm, Sweden in Stockholm, Sweden[2]..

When a system of When a system of atoms is cooled rather than bosons, the Bose- is cooled rather than bosons, the Bose-Einstein condensate is then sometimes called a Super Atom.[3]Einstein condensate is then sometimes called a Super Atom.[3]

KINETIC ENERGY AND TEMPERATURE

TEMPERATURE AND ENERGY ARE NOT THE TEMPERATURE AND ENERGY ARE NOT THE SAME THING!!!SAME THING!!!

Temperature is a measure of AVE. Kinetic EnergyTemperature is a measure of AVE. Kinetic Energy The higher the Temp, the greater the Kinetic The higher the Temp, the greater the Kinetic

EnergyEnergy

Kelvin temperature is directly proportional to Kelvin temperature is directly proportional to Average Kinetic Energy.Average Kinetic Energy.

Celcius vs Kelvin Scale; Kelvin = °C + 273Celcius vs Kelvin Scale; Kelvin = °C + 273

A 1° increment on the Kelvin scale = 1° on Celcius A 1° increment on the Kelvin scale = 1° on Celcius 3x Kelvin Temperature = 3x Kinetic Energy3x Kelvin Temperature = 3x Kinetic Energy Absolute Zero = temp. all molecular motion stopsAbsolute Zero = temp. all molecular motion stops

Temperature Scale ComparisonTemperature Scale Comparison

CelciusThirty is hot

Twenty is nice

Ten is cool Zero is ice

PressurePressure Gas pressure – collisions of gas particles Gas pressure – collisions of gas particles

with the surface of an object.with the surface of an object. Atmospheric Pressure – collision of “air Atmospheric Pressure – collision of “air

molecules with the surface of an object.molecules with the surface of an object. Barometer Barometer – instrument – instrument measures the height

of a column of mercury supported by air pressure

vacuum Normal atmospheric pressure pushing on a mercury barometer supports a column of Hg about 760 mm high = 1 standard atmosphere atmospheric barometric pressure pressure (forces Hg up the eudiometer 1 atm = 760 mm Hg = 30 in Hg = 14.7 psi = 101.3 kPa . tube)

Measuring air pressure –BarometersMeasuring air pressure –Barometers

Eudiometer760mmHg

At sea level (1atm)

Below sea level

Cave (2atm)

Higher than sea level on Moon (0atm)

Barometer Barometer on Mt. top on moon atmosphere 100 miles high 95% mcs 1st 5 mi. Medford Colorado EARTH Less No atmospheric atmospheric

pressure pressure

Boiling point – temperature at which the vapor pressure of a liquid = external pressureCan boil by: increasing temperature increases KE of mc’s or decreasing external pressure so mc’s already have enough KEAs elevation increases, atmospheric pressure decreases so boiling point decreases. 

CHANGES OF STATE – PHASE CHANGES are phase CHANGES OF STATE – PHASE CHANGES are phase

changes that ALWAYS involve energy changeschanges that ALWAYS involve energy changes..

Energy in = Endothermic (cools surroundings)

(melting) evaporation or boilingSOLID LIQUID GAS (freezing) condensation

Energy out = Exothermic (warms surroundings)

Melting, evap. and boiling are cooling processesFreezing and condensation are warming process

Evaporation VS BoilingEvaporation VS BoilingSimilarities Differences

-- Both involve a phase change: -- evaporation only occurs at the surface liquid gas -- boiling occurs throughout the body of the liq. -- both require energy -- evaporation occurs below the boiling point (boiling H20 requires 540 cal/g) -- boiling occurs at the boiling point -- both are cooling processes – mc’s with high KE escape, leaving slower, cooler ones behind

sublimation – the conversion of a solid to a gas without passing through the liquid state

Substances with very weak intermolecular forces are unable to hold molecules together so they are able to spread apart, preventing them from having a liquid phase, and forcing them to sublime.

Phase DiagramPhase Diagram Temperature Heat of vaporization Heat of fusion gas Boiling point - - - - - - - - - - - - - - - - - - - - - - liquid Melting point - - - - - - - - solid Time

During a phase change there is no temperature change because all of the heat energy is being converted into kinetic energy as the motion of the molecules increases.

Phase Diagram Phase Diagram Shows the relationship between solid, liquid Shows the relationship between solid, liquid

and vapor phases in a sealed container. and vapor phases in a sealed container. Each sections shows a pure phase.Each sections shows a pure phase.

Equilibrium

2 phases existing at the same time at a certain temp & pressure. (line separating 2 regions.)

Triple Point

Only condition that allows all 3 phases to exist at the same time. (where lines intersect)