atomic structure pp

8/14/2019 Atomic Structure Pp

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Atomic StructureAtomic StructureModern TheoryModern Theory


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Subatomic particlesSubatomic particles

ProtonsProtons

1.1. Positively charged particle located inPositively charged particle located in

nucleusnucleus2.2. Mass = 1.673 e 24 g or 1.0073 uMass = 1.673 e 24 g or 1.0073 u

3.3. Always moving (atomic vibration)Always moving (atomic vibration)

4.4. Composed on 2 Up quarks and 1 DownComposed on 2 Up quarks and 1 Down


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More Subatomic ParticlesMore Subatomic Particles

NeutronsNeutrons

1.1. Subatomic particle located in nucleusSubatomic particle located in nucleus

with no electrical chargewith no electrical charge2.2. Mass = 1.675 e 24 g or 1.0087 uMass = 1.675 e 24 g or 1.0087 u

3.3. Decays into proton, electron, andDecays into proton, electron, and

electron anti-neutrinoelectron anti-neutrino4.4. Composed of one Up quark and 2 DownComposed of one Up quark and 2 Down


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More Subatomic ParticlesMore Subatomic Particles

ElectronsElectrons

1.1. Very small negatively charged subatomicVery small negatively charged subatomic

particle in orbit around nucleusparticle in orbit around nucleus2.2. Mass = 1.1 E 29 g or 0.000 549 uMass = 1.1 E 29 g or 0.000 549 u

3.3. Mass = 1/1836 of protonMass = 1/1836 of proton

4.4. Moves rapidly and is easily acceleratedMoves rapidly and is easily accelerated


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DefinitionsDefinitions

Leptons: no perceptible internal structureLeptons: no perceptible internal structure

with spin (examples: electron, neutrino,with spin (examples: electron, neutrino,

muon)muon)

Hadrons: particles composed of quarksHadrons: particles composed of quarks

(examples: protons, neutrons)(examples: protons, neutrons)

Quarks: building blocks of hadronicQuarks: building blocks of hadronic

particles (in increasing size: Up, Down,particles (in increasing size: Up, Down,

Charm, Strange, Top, Bottom)Charm, Strange, Top, Bottom)


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Matter vs AntimatterMatter vs Antimatter

For every particle there is a correspondingFor every particle there is a corresponding

antiparticle. These particles andantiparticle. These particles and

antiparticles have identical mass and spinantiparticles have identical mass and spin

but opposite charges.but opposite charges.


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DefinitionsDefinitions

Atomic Number (Z): number of protons inAtomic Number (Z): number of protons in

the nucleus (if atom is electricallythe nucleus (if atom is electrically

balanced it will also be the # of electrons)balanced it will also be the # of electrons)

Atomic Mass (M): see definition in classAtomic Mass (M): see definition in class

Mass Number (A): sum of protons andMass Number (A): sum of protons and

neutrons in nucleusneutrons in nucleus

Nucleons: particles that make up theNucleons: particles that make up the

nucleus of an atomnucleus of an atom


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More DefinitionsMore Definitions

Element: pure form of substance, madeElement: pure form of substance, madeup of only one kind of atom -- elementsup of only one kind of atom -- elementsare simple substances that cannot beare simple substances that cannot be

decomposed or changed into anotherdecomposed or changed into anotherelement by chemical meanselement by chemical means

Atom: smallest particle of elementAtom: smallest particle of element

Molecule: 2 or more atoms bondedMolecule: 2 or more atoms bondedchemically together, has a definite,chemically together, has a definite,invariable composition and structureinvariable composition and structure


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IonsIons

Ions are atoms that have lost or gainedIons are atoms that have lost or gained

electronselectrons

CaCa loses 2 electrons: Caloses 2 electrons: Ca2+2+

20 p20 p++ 20 p20 p++

20 e20 e--

18 e18 e--


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IsotopesIsotopes

Isotopes are atoms of the same elementIsotopes are atoms of the same element

but with different number of neutronsbut with different number of neutrons

(mass numbers will be different but atomic(mass numbers will be different but atomic

numbers will be the same)numbers will be the same)

example: Boron example given in classexample: Boron example given in class


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Hydrogen IsotopesHydrogen Isotopes

Natural hydrogen (1 proton and 1 electron)Natural hydrogen (1 proton and 1 electron)

Deuterium (1 proton, 1 electron, 1Deuterium (1 proton, 1 electron, 1

neutron)neutron)

Tritium (1 proton, 1 electron, 2 neutrons)Tritium (1 proton, 1 electron, 2 neutrons)


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CompoundsCompounds

Compounds are two or more elementsCompounds are two or more elements

chemically joined (held together bychemically joined (held together by

chemical bonds)chemical bonds)

There is a fixed proportion of elements byThere is a fixed proportion of elements by

weightweight

Properties are different from componentsProperties are different from components

Compounds can be separated only byCompounds can be separated only by

chemical meanschemical means


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MixturesMixtures

Mixtures are two or more substancesMixtures are two or more substances

(elements or compounds or both) that do(elements or compounds or both) that do

not combine chemically during the mixing.not combine chemically during the mixing.

There is a variable proportion ofThere is a variable proportion of

componentscomponents

Properties remain the same as beforeProperties remain the same as before

mixingmixing

Parts can be separated by physical meansParts can be separated by physical means


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Mixture SubTypesMixture SubTypes

Heterogeneous: divide mixture into 2Heterogeneous: divide mixture into 2

halves and get different compositionhalves and get different composition

Homogeneous: divide mixture into 2Homogeneous: divide mixture into 2

halves and they are identicalhalves and they are identical


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More Mixture typesMore Mixture types

Emulsion: mixture of 2 immiscible liquidsEmulsion: mixture of 2 immiscible liquids

(ones that dont mix), examples = oil &(ones that dont mix), examples = oil &

vinegar dressing, paint, hand crmevinegar dressing, paint, hand crme

Alloy: mixture of 2 or more metals meltedAlloy: mixture of 2 or more metals melted

together having new and differenttogether having new and different

properties, examples: bronze, brass,properties, examples: bronze, brass,

pewterpewter Amalgam: mixture containing mercuryAmalgam: mixture containing mercury


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SolutionsSolutions

A solution is a liquid homogeneousA solution is a liquid homogeneous

mixture containing a dissolved substancemixture containing a dissolved substance

1.1. Solvent = component in largestSolvent = component in largest

concentrationconcentration

2.2. Solute = component in smallestSolute = component in smallest

concentrationconcentration

3.3. Aqueous = solvent is waterAqueous = solvent is water

4.4. Tincture = solvent is alcoholTincture = solvent is alcohol


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More on SolutionsMore on Solutions

Dilute solutions: small amount of soluteDilute solutions: small amount of solute

compared to amount of solventcompared to amount of solvent

Concentrated solution: contains moreConcentrated solution: contains more

solute than a dilute solutionsolute than a dilute solution

Saturated solution: when solvent cannotSaturated solution: when solvent cannot

hold any more solute at a givenhold any more solute at a given

temperaturetemperature


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TypesTypes

Suspension: heterogeneous mixtureSuspension: heterogeneous mixture

where visible particles will settle outwhere visible particles will settle out

Colloids: particles small enough that theyColloids: particles small enough that they

do not settle out and are usually too smalldo not settle out and are usually too small

to be visible (examples = gelatin, coldto be visible (examples = gelatin, cold

cream, lipstick, shaving cream)cream, lipstick, shaving cream)

Emulsion: colloid of 2 liquids (examples =Emulsion: colloid of 2 liquids (examples =

mayonnaise or salad dressing)mayonnaise or salad dressing)


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More TypesMore Types

Gels: colloid in which liquid particles areGels: colloid in which liquid particles are

spread out in a solid (examples = gelatin,spread out in a solid (examples = gelatin,

jelly, stick deodorant)jelly, stick deodorant)

Aerosol: colloid in which solid or liquidAerosol: colloid in which solid or liquid

particles are suspended in a gasparticles are suspended in a gas

(examples: fog or smoke)(examples: fog or smoke)


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Mixture Separation TechniquesMixture Separation Techniques

Filtration: part must be solubleFiltration: part must be soluble Distillation: must know boiling points of twoDistillation: must know boiling points of two

liquidsliquids

Recrystallization: must know melting pointsRecrystallization: must know melting pointsand crystal structuresand crystal structures

Solubility: must know nature of substancesSolubility: must know nature of substances

Size, magnetic/electrical attraction, densitySize, magnetic/electrical attraction, density Chromatography: must know affinity toChromatography: must know affinity to

surface versus affinity to solvent usedsurface versus affinity to solvent used


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Law of Conservation ofLaw of Conservation of

Mass/EnergyMass/Energy

Finite amount of matter and energy inFinite amount of matter and energy in

universeuniverse

Matter to energy and energy to matterMatter to energy and energy to matter

changes occurchanges occur

Energy can be changed in form (seeEnergy can be changed in form (see

examples in class) without loss to universeexamples in class) without loss to universe

Matter can be changed in form or stateMatter can be changed in form or state

without loss to universewithout loss to universe


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Laws of ThermodynamicsLaws of Thermodynamics

First law: conservation of energyFirst law: conservation of energy

Second law: entropy increases in allSecond law: entropy increases in all

natural processesnatural processes

Third law: we cannot reach absolute zeroThird law: we cannot reach absolute zero

Zeroth law: If TZeroth law: If Taa= T= T

bband Tand T

bb= T= T

ccthen Tthen T

aa==

TTcc (thermal equilibrium in balance)(thermal equilibrium in balance)


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4 Forces in Nature4 Forces in Nature

Gravity: force is dependent on mass andGravity: force is dependent on mass and

the distance between objectsthe distance between objects

Electromagnetism: affects all electricallyElectromagnetism: affects all electrically

charged objectscharged objects

Strong Nuclear Force: binds together theStrong Nuclear Force: binds together the

particles of nucleusparticles of nucleus

Weak Nuclear Force: responsible forWeak Nuclear Force: responsible for

nuclear decay (radioactivity)nuclear decay (radioactivity)


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MolesMoles

The number of moles of any substance isThe number of moles of any substance ischaracterized by the coefficientcharacterized by the coefficient

The mass of one mole of a substance is shownThe mass of one mole of a substance is shown

in the formula massin the formula mass One mole of any substance containsOne mole of any substance contains

6.02 E 23 particles6.02 E 23 particles

One mole of any gas occupies 22.4 L of volumeOne mole of any gas occupies 22.4 L of volumeat standard temperature and pressureat standard temperature and pressure

atomic structure pp

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