unit 2 atomic/nuclear theory/periodic patterns. unit sequence dayobjectivesassessments activities...

Unit 2 Atomic/Nuclear Unit 2 Atomic/Nuclear Theory/Periodic PatternsTheory/Periodic Patterns

Unit SequenceUnit SequenceDayDay ObjectivesObjectives AssessmentsAssessments Activities & Activities &

AssignmentsAssignments

11 Hook InterestHook Interest Data & Observations, Data & Observations, Gold penny taped in Gold penny taped in notebook, 1 page notebook, 1 page storystory

Alchemist’s Dream Alchemist’s Dream Lab, Write 1 page Lab, Write 1 page story of fictional story of fictional discovery & discovery & consequencesconsequences

2 2 Overview of Atomic Overview of Atomic Theory Theory

Fireworks Poster Fireworks Poster Project RubricProject Rubric

History, Chemistry, History, Chemistry, Spectra of FireworksSpectra of Fireworks

22 Review basic Review basic Atomic Structure Atomic Structure

Previous knowledge in Previous knowledge in notes, Completed notes, Completed assignment, assignment, Cooperative QuizCooperative Quiz

Use atomic mass & Use atomic mass & number to draw Bohr number to draw Bohr Models of elements 1-Models of elements 1-18 odd18 odd

Quiz Quiz

3,4,5,63,4,5,6 History of Atomic History of Atomic Theory – Dalton, Theory – Dalton, Thomson, Thomson, Rutherford, Rutherford, (Emission Spectra (Emission Spectra & Photoelectric & Photoelectric effect) Bohr effect) Bohr

Lecture discussions, Lecture discussions, pair questions, Dalton pair questions, Dalton Quiz – Informal, Quiz – Informal, Thomson Quiz, Thomson Quiz, Rutherford quiz, Rutherford quiz, Comparative QuizComparative Quiz

Lectures, Cathode Ray Lectures, Cathode Ray Demos, Video Clips, Demos, Video Clips, Flame Tests Lab, Flame Tests Lab, Emission SpectraEmission Spectra

Unit SequenceUnit SequenceDaDayy

ObjectivesObjectives AssessmentsAssessments Activities & AssignmentsActivities & Assignments

7 7 Isotopes, Avg Isotopes, Avg Atomic Mass, Atomic Mass, IonsIons

Book questions, Book questions, Worksheet – Problem Worksheet – Problem Solving to be Solving to be developed / Quizdeveloped / Quiz

8-8-1010

Radioactivity- Radioactivity- Designing Designing ExperimentsExperiments

Lab check points, Lab check points, Graphical sharing on doc Graphical sharing on doc viewerk, data & viewerk, data & observations in NBobservations in NB

Radioactivity Shielding Radioactivity Shielding Lab – Practice Day 1, Lab – Practice Day 1, Collect Good Data Day 2, Collect Good Data Day 2, HW: Graph, Share Data HW: Graph, Share Data Day 3Day 3

½ Lives½ Lives Graphical ResultsGraphical Results

½ Life Quiz½ Life Quiz½ Lives Blocks½ Lives Blocks

½ Life Problems½ Life Problems

1111 Types of Types of RadioactivityRadioactivity

Informal QuizInformal Quiz Notes & Geiger Counter Notes & Geiger Counter DemosDemos

Book Questions about Book Questions about basics & applicationsbasics & applications

1212 Nuclear Nuclear EquationsEquations

Discuss, Review & QuizDiscuss, Review & Quiz Styrofoam balls demo, Styrofoam balls demo, Write equations for Write equations for Uranium decay series Uranium decay series



1313 Understand Understand Quantum Quantum MechanicsMechanics

Quiz PartnerQuiz Partner Book questions, Demo Book questions, Demo Standing Waves, Video – Standing Waves, Video – Orbitals, Slides, Orbitals. Orbitals, Slides, Orbitals.

1414 Electron Electron ConfigurationsConfigurations

Discuss as show config Discuss as show config vs diagram from H vs diagram from H Na, Na,

Write configurations 1-Write configurations 1-35 odd35 odd

1515 Periodic Patterns Periodic Patterns of Electron of Electron Configurations - Configurations -

Quiz – configs, Noble Quiz – configs, Noble Gas configurations & Gas configurations & drawingdrawing

Discovery discussion & Discovery discussion & decorate patterns of decorate patterns of periodic table, write periodic table, write Noble Gas configurations Noble Gas configurations of 1-35 oddof 1-35 odd

1616 History of History of Periodic Table Periodic Table

Progress on mystery, Progress on mystery, discussion feedback, discussion feedback, quiz partnerquiz partner

Cochran – Periodic Table Cochran – Periodic Table Mystery, Book questions, Mystery, Book questions, Notes on HistoryNotes on History

1717 Patterns of Patterns of PeriodicityPeriodicity

-Reactivity, Reactivity, bonding, ions, bonding, ions, atomic radius, atomic radius, ionization ionization energy, energy, electronegativityelectronegativity

Comparing Periodic Comparing Periodic GroupsGroups

Laserdisc demos of Laserdisc demos of radioactivity, decorate radioactivity, decorate bonds & ions on blank, bonds & ions on blank, use data to make graphs use data to make graphs & interpret patterns& interpret patterns

Element Samp;e Element Samp;e ObservationsObservations



1313 Understand Understand Patterns of Patterns of Atomic Radius & Atomic Radius & their Basistheir Basis

Rank atoms vertically & Rank atoms vertically & horizontally – small to horizontally – small to large.large.

Explain trend of each. Explain trend of each.

Find patterns in pictures Find patterns in pictures of radii. Examine of radii. Examine ExplanationExplanation

1414 Understand how Understand how Periodic Table is Periodic Table is organizedorganized

Periodic Card SetPeriodic Card Set

Old Periodic Table Fill in Old Periodic Table Fill in BlankBlank

1515

1616

1717

Vocab 2AVocab 2A• AtomAtom• Law of Definite Law of Definite

ProportionsProportions• Law of Conservation of Law of Conservation of

MassMass• Cathode ray Cathode ray • Cathode ray tubeCathode ray tube• ElectronElectron• NucleusNucleus• ProtonProton• NeutronNeutron• Atomic mass unitAtomic mass unit• Atomic numberAtomic number• Atomic massAtomic mass• IonIon• IsotopeIsotope

• Electromagnetic Electromagnetic radiationradiation

• frequencyfrequency• WavelengthWavelength• QuantumQuantum• Photoelectric effectPhotoelectric effect• PhotonPhoton• Line spectrumLine spectrum• Ground stateGround state• Excited stateExcited state• Quantum mechanical Quantum mechanical

modelmodel• OrbitalOrbital• SublevelSublevel• Electron configurationElectron configuration

Vocabulary 2BVocabulary 2B

IsotopeIsotopenuclear reactornuclear reactorRadioisotopeRadioisotopenuclear weaponnuclear weaponRadioactivityRadioactivityhalf lifehalf lifeRadiationRadiationnuclear equationnuclear equationFissionFissionpositronpositronFusionFusionradiocarbon datingradiocarbon dating

Radioactive decayRadioactive decaycritical masscritical massAlpha particleAlpha particlenuclear bombardmentnuclear bombardmentBeta particleBeta particlestrong nuclear forcestrong nuclear forceGamma rayGamma ray plasmaplasmaNuclear chain reactionNuclear chain reactiondosimeterdosimeter

Atom Builder ActivityAtom Builder Activity

• http://www.pbs.org/wgbh/aso/tryit/http://www.pbs.org/wgbh/aso/tryit/atom/ atom/

• For each addition to the atom (Up to For each addition to the atom (Up to Stable Carbon) record the following:Stable Carbon) record the following:

Element Protons Neutrons

Electrons

Radioactive?

Ionized? Stable?

Bohr Models of Atoms – Parts (1 of Bohr Models of Atoms – Parts (1 of 3)3)

NucleusNucleus1 amu1 amu00NeutronNeutron

Orbiting Orbiting nucleusnucleus

1/1837 1/1837 amuamu

-1-1ElectronElectron

NucleusNucleus1 amu1 amu+1+1ProtonProton

LocationLocationMassMassChargeChargePartPart

Determining the Part (2 of Determining the Part (2 of 3)3)

= atomic mass (larger # w/ = atomic mass (larger # w/ decimal, round) – atomic #decimal, round) – atomic #

NeutronsNeutrons

= atomic number (smaller = atomic number (smaller whole #) from periodic table whole #) from periodic table (assumes 0 charge, or (assumes 0 charge, or neutral)neutral)

ElectronElectronss

= atomic number (smaller = atomic number (smaller whole #) from periodic tablewhole #) from periodic table

ProtonsProtons

How to DetermineHow to DeterminePartPart

Drawing Bohr Models (3 of Drawing Bohr Models (3 of 3)3)Determine number of protons, electrons & Determine number of protons, electrons &

neutrons in atom.neutrons in atom.

Draw protons (+) & neutrons (0) in Draw protons (+) & neutrons (0) in nucleus.nucleus.

Draw electrons in circles around nucleus:Draw electrons in circles around nucleus:

- 2 maximum on 1- 2 maximum on 1stst level. level.

- 8 maximum on 2- 8 maximum on 2ndnd level. level.

- 18 maximum on 3- 18 maximum on 3rdrd level. level.

Asmt: Draw elements 1-18 odd (even XC)Asmt: Draw elements 1-18 odd (even XC)

Alchemist’s Dream Review (1 Alchemist’s Dream Review (1 of 2)of 2)

Q: How do you tell if it is really gold?Q: How do you tell if it is really gold?• Archimedes Principle: Determine the volume by Archimedes Principle: Determine the volume by

displacement and then confirm the density. displacement and then confirm the density. Q: What did the salty vinegar do?Q: What did the salty vinegar do?• Dark pennies have black CuO oxidation.Dark pennies have black CuO oxidation.• Acid in vinegar & salt reduce the CuAcid in vinegar & salt reduce the Cu+2+2 back to back to

CuCu00 to reshine the penny. to reshine the penny.Q: How did the pennies turn silver?Q: How did the pennies turn silver?• Zinc plates on the outside of the copper.Zinc plates on the outside of the copper.Q: How did they turn to gold in the flame?Q: How did they turn to gold in the flame?• Heating melts the zinc into the copper to form Heating melts the zinc into the copper to form

brass!brass!

Alchemist’s Dream Review (2 Alchemist’s Dream Review (2 of 2)of 2)

Q: Was the removal of black CuO a chemical or Q: Was the removal of black CuO a chemical or physical change?physical change?

A: It chemically changed from black copper salt A: It chemically changed from black copper salt to metallic copper.to metallic copper.

Q: Is brass a mixture or a compound?Q: Is brass a mixture or a compound?

A: Brass is a mixture and an alloy.A: Brass is a mixture and an alloy.

Q: Is the mixture homogeneous or Q: Is the mixture homogeneous or heterogeneous?heterogeneous?

A: Ours varied by depth and color. So they were A: Ours varied by depth and color. So they were heterogeneous. Manufacturers produce heterogeneous. Manufacturers produce homogeneous brass.homogeneous brass.

Development of Atomic Development of Atomic TheoryTheory

History of the atomHistory of the atom

• Not the history of atom, but the idea of Not the history of atom, but the idea of the atom.the atom.

• Original idea Ancient Greece (400 Original idea Ancient Greece (400 B.C.)B.C.)

• Democritus and Leucippus- Greek Democritus and Leucippus- Greek philosophers.philosophers.

John DaltonJohn Dalton

•BritishBritish•A small town A small town

school teacher school teacher at the age of at the age of 12.12.

• Introduced his Introduced his atomic theory atomic theory in 1803.in 1803.

Previous FindingsPrevious Findings1. Law of Conservation of Mass1. Law of Conservation of Mass

Matter is neither created or destroyed in a Matter is neither created or destroyed in a chemical reaction. (Antoine Lavoisier)chemical reaction. (Antoine Lavoisier)

2.2. Law of Definite ProportionsLaw of Definite Proportions

The percentage by mass of elements in a The percentage by mass of elements in a compound is constant for any sample. Ex: compound is constant for any sample. Ex: HH22OO

3. Law of Multiple Proportions3. Law of Multiple Proportions

Compounds composed of the same two Compounds composed of the same two elements differ in one element by simple elements differ in one element by simple ratios.ratios.

Ex: CO vs CO2; H2O vs H2O2Ex: CO vs CO2; H2O vs H2O2

Law of Definite ProportionsLaw of Definite Proportions

•Each compound has a specific ratio of elements.

• It is a ratio by mass.•Water has a mass of 18 grams

hydrogen 2 atoms x 1.0 gramsoxygen 1 atom x 16 grams

•The ratio is always 8 grams of oxygen for each gram of hydrogen (2 g H to 16 g O or 1 g H to 8 g O). (2 g H to 16 g O or 1 g H to 8 g O).

Law of Multiple ProportionsLaw of Multiple Proportions

• Two elements or more elements may Two elements or more elements may form more than one compound if form more than one compound if they have different whole number they have different whole number ratio of each element.ratio of each element.

• Example: Example: waterwater HH22OO

hydrogen peroxidehydrogen peroxide HH22OO22

Daltons Atomic TheoryDaltons Atomic Theory

1.1. All matter is composed of tiny indivisible All matter is composed of tiny indivisible particles called atomsparticles called atoms

2.2. All atoms of the same element are identicalAll atoms of the same element are identical

3.3. Different elements have different types of Different elements have different types of atomsatoms

4.4. Compounds are formed from simple Compounds are formed from simple combinations of atoms of different elements.combinations of atoms of different elements.

5.5. In a chemical reaction atoms are simply In a chemical reaction atoms are simply rearranged.rearranged.

*Activity: Ball & Stick Reactions*Activity: Ball & Stick Reactions

Picture Dalton’s Atomic Picture Dalton’s Atomic TheoryTheory

Updates to Dalton’s TheoryUpdates to Dalton’s Theory

1a. Atoms are divisible into protons, 1a. Atoms are divisible into protons, neutrons & electrons (& even neutrons & electrons (& even smaller!). smaller!).

1b. In nuclear decay they actually fall 1b. In nuclear decay they actually fall apart!apart!

2. All atoms of a single element have 2. All atoms of a single element have the same number of protons, but not the same number of protons, but not neutrons. (isotopes)neutrons. (isotopes)

4. Compounds may be very complex!4. Compounds may be very complex!

Dalton’s Atomic Theory QuizDalton’s Atomic Theory Quiz

1.1. What year was his theory published?What year was his theory published?2.2. Which previous finding defined Which previous finding defined

compounds as having consistent compounds as having consistent percent compositions?percent compositions?

3.3. How did Dalton describe chemical How did Dalton describe chemical reactions?reactions?

4.4. How can atoms of the same element How can atoms of the same element be different?be different?

Cathode RaysCathode Rays

• Tape Lab – Static Tape Lab – Static electricity attractions & electricity attractions & repulsions. Where do repulsions. Where do the charges originate?the charges originate?

• An evacuated glass An evacuated glass tube when placed in an tube when placed in an electric field electric field

• Crooke’s observed a Crooke’s observed a glowing inside.glowing inside.

• Thomson repeated Thomson repeated Crooke’s experiment Crooke’s experiment and did additional and did additional experiments.experiments.

(-) (+)

Thomson’s Experiment #1Thomson’s Experiment #1• Setup: A cross was Setup: A cross was

placed in the path placed in the path of the glowing of the glowing beam. (D?)beam. (D?)

• Observation: A Observation: A shadow appeared shadow appeared on the anode (+) on the anode (+) side. (D?)side. (D?)

• Interpretation: The Interpretation: The rays come from the rays come from the cathode (-) side. cathode (-) side.

Cathode (-)

Anode (+)

Thomson’s ExperimentThomson’s Experiment

Voltage source

+-

Vacuum tube

Metal Disks


Voltage source

+-

Passing an electric current makes a beam Passing an electric current makes a beam appear to move from the negative to the appear to move from the negative to the

positive endpositive end


Voltage source

+-

Thomson’s Experiment #2Thomson’s Experiment #2• Setup: The cathode Setup: The cathode

ray tube was placed ray tube was placed in an electric field: in an electric field: (-) electrode on top, (-) electrode on top, (+) electrode on (+) electrode on bottom. (DPath?)bottom. (DPath?)

• Observation: The Observation: The cathode rays were cathode rays were attracted towards attracted towards the (+) electrode. the (+) electrode. (D?)(D?)

• Interpretation: Interpretation: Cathode rays must Cathode rays must be negative (-).be negative (-).

http://www.aip.org/history/electron/jjappara.htm

Thomson’s Experiment #3Thomson’s Experiment #3

• Setup: Cathode rays Setup: Cathode rays were placed in a were placed in a magnetic field.magnetic field.

• Observation: Observation: Cathode rays are Cathode rays are bent perpendicular bent perpendicular to the magnetic to the magnetic field.field.

• Interpretation: Interpretation: Cathode rays are not Cathode rays are not a form of light.a form of light.

Thomson’s Experiment #4Thomson’s Experiment #4• Setup: A glass wheel was placed on Setup: A glass wheel was placed on

a level track inside the cathode ray a level track inside the cathode ray tube.tube.

• Observation: Cathode rays can Observation: Cathode rays can rotate the glass wheel.rotate the glass wheel.

• Interpretation: Cathode rays are Interpretation: Cathode rays are particles with mass.particles with mass.

Thomson Experiment #5Thomson Experiment #5

• Setup: Thomson made cathode ray Setup: Thomson made cathode ray tubes with a variety of different tubes with a variety of different gases & metal electrodes in the tube.gases & metal electrodes in the tube.

• Observation: Every tube produced Observation: Every tube produced the same cathode rays.the same cathode rays.

• Interpretation: Cathode rays are Interpretation: Cathode rays are fundamental to matter. He called fundamental to matter. He called cathode rays “electrons!” cathode rays “electrons!” Discovered in 1897.Discovered in 1897.

Thomson’s Plum Pudding Thomson’s Plum Pudding ModelModel

• Thomson concluded Thomson concluded that all atoms must that all atoms must have negative have negative charges and positive charges and positive charges to balance charges to balance them.them.

• Thomson assumed Thomson assumed that (+) & (-) that (+) & (-) charges would be charges would be evenly distributed.evenly distributed.

Thomson’s Atomic Thomson’s Atomic ModelModel

Thomson believed that the electrons were like plums embedded in a positively charged “pudding,” thus it was called the “plum

pudding” model.

Uses of cathode raysUses of cathode rays• 1. A cathode ray tube (CRT) is widely used in research 1. A cathode ray tube (CRT) is widely used in research

laboratories to convert any signal (electrical, sound, etc) laboratories to convert any signal (electrical, sound, etc) into visual signals. These are called CRT or oscilloscopes. into visual signals. These are called CRT or oscilloscopes.

• 2. CRT is the basic component in all television and 2. CRT is the basic component in all television and computer screens. The signals are sent to the vertical and computer screens. The signals are sent to the vertical and horizontal deflecting plates, which produce a pattern on the horizontal deflecting plates, which produce a pattern on the fluorescent screen. fluorescent screen.

• High energy cathode rays when stopped suddenly produce High energy cathode rays when stopped suddenly produce X-rays. The X-rays have many medical and research X-rays. The X-rays have many medical and research applications. applications.

Thomson’s Atomic Theory Thomson’s Atomic Theory QuizQuiz1.1. How did Thomson know that the rays How did Thomson know that the rays

came from the cathode?came from the cathode?2.2. What did Thomson conclude from What did Thomson conclude from

cathode rays being bent by a cathode rays being bent by a magnet?magnet?

3.3. How did Thomson know cathode rays How did Thomson know cathode rays were fundamental to matter?were fundamental to matter?

4.4. In Thomson’s model of the atom In Thomson’s model of the atom where is the positive charge?where is the positive charge?

Millikan’s Oil Drop ExperimentMillikan’s Oil Drop Experiment

• the charge of an the charge of an electron with electron with this oil-drop this oil-drop experiment. –experiment. –1.6 x 101.6 x 10-19-19 coulombcoulomb

• Thomson and Thomson and Millikan Millikan calculated the calculated the mass of the mass of the electron to be electron to be 9.1 x 109.1 x 10-28-28 g. g. This is 1/1837 This is 1/1837 the mass of a the mass of a Hydrogen atom.Hydrogen atom.

Becquerel/CurriesBecquerel/Curries• Becquerel - Radioactivity

• Curie – Discovered radioactive Curie – Discovered radioactive elements of radium and poloniumelements of radium and polonium

RadioactivityRadioactivity

1.1. Alpha particle – is two protons and two Alpha particle – is two protons and two neutrons bound together and is emitted neutrons bound together and is emitted from the nucleus, 2+ charge, 4.0 grams, from the nucleus, 2+ charge, 4.0 grams, least dangerous.least dangerous.

2.2. Beta particle – an electron emitted from Beta particle – an electron emitted from the nucleus 1- chargethe nucleus 1- charge

3.3. Gamma rays are high energy Gamma rays are high energy electromagnetic waves emitted from the electromagnetic waves emitted from the nucleus, most dangerous.nucleus, most dangerous.

RadioactivityRadioactivity

• Alpha – largeAlpha – largeRelatively slowRelatively slow

• Beta – much smallerBeta – much smallerRelative fastRelative fast

• Gamma – no massGamma – no massPure energyPure energy

Travels at the Travels at the

Speed of lightSpeed of light

Ernest RutherfordErnest Rutherford

• New ZealanderNew Zealander

• Discoverer of Discoverer of alpha, beta & alpha, beta & gamma radiation.gamma radiation.

• Discovered nucleus Discovered nucleus of atom in 1912.of atom in 1912.

• Laserdisc demo – Laserdisc demo – Side 2, Chapter 20Side 2, Chapter 20

Rutherford’s Experimental Rutherford’s Experimental DesignDesign

• Uranium alpha Uranium alpha emitter. emitter.

• Slits to focus Slits to focus radiationradiation

• Gold foil target.Gold foil target.

• Scintillation screen Scintillation screen of zinc sulfide to of zinc sulfide to flash when hit.flash when hit.

Rutherford’s PredictionRutherford’s Prediction

Positive alpha Positive alpha particles would go particles would go straight through or straight through or have minor have minor deflections due to deflections due to the electrons the electrons embedded in a sea embedded in a sea of positively of positively charged matter.charged matter.

Rutherford’s ObservationsRutherford’s Observations

Interpreting the ResultsInterpreting the Results• Most positive alpha particles went straight through or were Most positive alpha particles went straight through or were

slightly deflected.slightly deflected.• Therefore the atom is mostly empty space.Therefore the atom is mostly empty space.• A few positive alpha particles bounced back radically!A few positive alpha particles bounced back radically!• Thus the atom must have a large concentration of positive Thus the atom must have a large concentration of positive

charge!charge!

Rutherford’s Atomic ModelRutherford’s Atomic Model

Development of the Bohr Development of the Bohr ModelModel

• In 1913 Danish In 1913 Danish physicist Neils Bohr physicist Neils Bohr proposed a new proposed a new model of the atom.model of the atom.

• Bohr’s Model Bohr’s Model explained the explained the emission and emission and absorption patterns absorption patterns of light discovered of light discovered by Bunsen in flames by Bunsen in flames & lamps.& lamps.

Emission LampsEmission Lamps

Emission SpectraEmission Spectra• Each element emits a unique set of bright line Each element emits a unique set of bright line

wavelengths.wavelengths.

Emission Spectra of All the Emission Spectra of All the ElementsElements

•http://chemistry.beloit.edu/bluelight/moviepages/em_el.htm

•http://jersey.uoregon.edu/vlab/elements/Elements.html

•http://www.webelements.com/

http://chemistry.beloit.edu/bluelight/moviepages/em_el.htm

http://chemistry.beloit.edu/bluelight/moviepages/em_el.htm

http://jersey.uoregon.edu/vlab/elements/Elements.html

http://jersey.uoregon.edu/vlab/elements/Elements.html

http://www.webelements.com/

4 Principles of the Bohr 4 Principles of the Bohr ModelModel

1)Electrons assume only certain orbits around 1)Electrons assume only certain orbits around the nucleus. These orbits are stable and the nucleus. These orbits are stable and called "stationary" orbits.called "stationary" orbits.

2)Each orbit has an energy associated with it. 2)Each orbit has an energy associated with it. The lowest energy levels are close to the The lowest energy levels are close to the nucleus. The farther from the nucleus nucleus. The farther from the nucleus corresponds to higher energy levels. corresponds to higher energy levels. Electrons tend to occupy the lowest energy Electrons tend to occupy the lowest energy levels available.levels available.

3)Light is emitted when an electron jumps from 3)Light is emitted when an electron jumps from a higher orbit to a lower orbit. Light is a higher orbit to a lower orbit. Light is absorbed when it jumps from a lower to absorbed when it jumps from a lower to higher orbit.higher orbit.

4)The quantity of energy and wavelength of 4)The quantity of energy and wavelength of light emitted or absorbed is given by the light emitted or absorbed is given by the difference between the two orbit energies. difference between the two orbit energies. (Quantum Leaps!)(Quantum Leaps!)

• With these conditions With these conditions Bohr was able to Bohr was able to explain the stability of explain the stability of atoms as well as the atoms as well as the emission spectrum of emission spectrum of hydrogen. hydrogen.

• Line spectra Line spectra correspond to correspond to quantum leaps quantum leaps between levels of between levels of specific energies.specific energies.

• Violet light Violet light corresponds to high corresponds to high energy quantum leaps energy quantum leaps while red light while red light corresponds to low corresponds to low energy. ROYGBIVenergy. ROYGBIV

Excited State

Excited State

Ground State

Semi-Excited State

Green lightemitted

Red lightemitted

Excited vs Ground StatesExcited vs Ground States• Light is absorbed when electrons jump up Light is absorbed when electrons jump up

to higher “excited” energy levels.to higher “excited” energy levels.

• Light is emitted when electrons jump back Light is emitted when electrons jump back down to their lowest energy “ground” down to their lowest energy “ground” state energy levels.state energy levels.

• Animated Absorption & Emission

• Fluorescent lights are constantly exciting Fluorescent lights are constantly exciting gas atoms to emit light by passing a gas atoms to emit light by passing a stream of electrons through the interior stream of electrons through the interior gas.gas.

http://earthguide.ucsd.edu/earthguide/diagrams/absorption/

The Sun’s SpectraThe Sun’s Spectra•Many elements Many elements

can be can be identified by identified by their unique their unique lines.lines.

•Helium was 1Helium was 1stst discovered in discovered in the Sun’s the Sun’s (Helios) (Helios) spectrumspectrum

Emission vs AbsorptionEmission vs Absorption

Colors Lab A. Flame TestsColors Lab A. Flame Tests

NO DOUBLE DIPPING!NO DOUBLE DIPPING!Asthmatics may be excusedAsthmatics may be excusedTest 10 known compounds & 3 unlabeled to identify.Test 10 known compounds & 3 unlabeled to identify.Make data table:Make data table:

## Salt Salt FormulaFormula

Salt Salt AppearanceAppearance

Flame Color & Flame Color & EffectsEffects

Colors Lab B. Spectral Colors Lab B. Spectral Emissions Emissions

LamLamp #p #

# of # of LineLiness

Colors Line Colors Line PatternPattern

ID ID ElemenElementt

EvidenceEvidence

Comparing Atomic ModelsComparing Atomic ModelsDaltonDalton ThomsonThomson RutherforRutherfor

ddBohrBohr

Picture Picture of of Atomic Atomic ModelModel

EvidencEvidencee

Molecular Weight & Molar Molecular Weight & Molar MassMass

Definitions:Definitions:

Molecular weight – the sum of all the Molecular weight – the sum of all the atomic masses of all the atoms atomic masses of all the atoms composing the molecule in terms of amu.composing the molecule in terms of amu.

Molar mass – the mass of a mole of a Molar mass – the mass of a mole of a substance in terms of grams.substance in terms of grams.

Mole – the gram equivalent of molecular Mole – the gram equivalent of molecular weight.weight.

Molecular Weight vs Molar Molecular Weight vs Molar MassMassWater – HWater – H2200

2 x H atoms2 x H atoms

2 x 1.007942 x 1.00794

= 2.01588= 2.01588

1 x O atom1 x O atom

1 x 15.9991 x 15.999

Sum = 2.01588 + Sum = 2.01588 + 15.99915.999

= 18.016 amu= 18.016 amu

Water – HWater – H22OO

Molar mass = gram Molar mass = gram equivalent of the equivalent of the molecular weightmolecular weight

= 18.016 g= 18.016 g

Percent Composition Percent Composition

• Percent Composition – the percent by Percent Composition – the percent by mass of each element in a mass of each element in a compound.compound.

Percent Composition of Percent Composition of WaterWaterWater – HWater – H2200

2 x H atoms2 x H atoms

2 x 1.007942 x 1.00794

= 2.01588= 2.01588

1 x O atom1 x O atom

1 x 15.9991 x 15.999

Sum = 2.01588 + Sum = 2.01588 + 15.99915.999

= 18.016 amu or g= 18.016 amu or g

% = (part / whole)x100% = (part / whole)x100

% H = ?% H = ?

= (2.01588/18.016)100= (2.01588/18.016)100

= 11.189%= 11.189%

%O = ?%O = ?

= (15.999/18.016)100= (15.999/18.016)100

= 88.804%= 88.804%

Mole ProportionsMole Proportions

44.0 g27.0 g4.0 gconstant # = ?

44,000,000 amu

27,000,000 amu

4,000,000amu

1,000,000

44,000amu27,000amu4000 amu1000

440 amu270 amu40 amu10

44.0 amu27.0 amu4.0 amu1

CO2AlHe#

Moles!Moles!A mole has 3 characteristicsA mole has 3 characteristics

1.1. A mole is the molecular weight of a substance A mole is the molecular weight of a substance in grams. in grams.

• This is called the molar mass.This is called the molar mass.

2. 2. A mole of any substance will have the same A mole of any substance will have the same number of particles (atoms or molecules).number of particles (atoms or molecules).

• A mole always has 6.02x10A mole always has 6.02x102323 particles for any particles for any substance.substance.

• 6.02x106.02x102323 is called Avogadro’s Number. is called Avogadro’s Number.

3.3. A mole of any gas at standard temperature and A mole of any gas at standard temperature and pressure has the same volume.pressure has the same volume.

• Molar volume is 22.4L for any gas.Molar volume is 22.4L for any gas.

Particles(atoms orMolecules)

Mole Chart (1)Mole Chart (1)

MolesMass (g) X ÷

÷ x

MW

MM

A# 6.02x106.02x102323

MM = Molar

mass in grams

MW = molecular weight in

grams

Atomic & Nuclear Atomic & Nuclear ChemistryChemistry

Geiger Counter DemosGeiger Counter DemosSampleSample Counts per Counts per

MinuteMinuteReason Reason

HumansHumans

NaCl vs KClNaCl vs KCl

Smoke Smoke DetectorDetector

Old Fashioned Old Fashioned Lantern MantleLantern Mantle

Old Glow in the Old Glow in the Dark ClockDark Clock

Uranium OreUranium Ore

Radioactivity (PS1 Ch26, )Radioactivity (PS1 Ch26, )

Blocked by 1ft Blocked by 1ft of concrete or of concrete or few inches of few inches of

leadlead

Sheet Sheet metalmetal

Blocked Blocked by paperby paper

PenetratioPenetrationn

High energy High energy photonphoton

1 electron1 electron2 2 protons,protons,

2 2 neutronsneutrons

CompositioCompositionn

0 0 (movie)-1-1+2+2ChargeCharge

0 amu0 amu1/1837 1/1837 amuamu

4 amu4 amuMassMass

SymbolSymbol

GammaGammaBetaBetaAlphaAlphaTypes of Types of

RadiationRadiation

Alpha EmissionAlpha Emission

263 Sg106

4 He

2+

259 Rf104

http://www.remm.nlm.gov/alpha_animation.htm

• The unstable nucleus simultaneously The unstable nucleus simultaneously ejects two neutrons and two protons, ejects two neutrons and two protons, which correspond to a helium which correspond to a helium nucleus. nucleus.

• The emission of gamma photons is a The emission of gamma photons is a secondary reaction that occurs a few secondary reaction that occurs a few thousandths of a second after the thousandths of a second after the disintegration. disintegration.



Beta EmissionBeta Emission

14 C 6

0 e-1

+14 N 7

+

Gamma RadiationGamma Radiation

Radioactivity Shielding LabRadioactivity Shielding Lab

Essential Question:Essential Question:

There are a variety of medical There are a variety of medical diagnostic equipment which use diagnostic equipment which use radioactive materials inside. What is radioactive materials inside. What is the most efficient way for the most efficient way for manufacturers to cut down exposure manufacturers to cut down exposure for patients & medical staff?for patients & medical staff?

Materials:Materials:

Geiger Counter, Lead box, Uranium Geiger Counter, Lead box, Uranium Ore Sample, Ruler, Stop Watch, Ore Sample, Ruler, Stop Watch,

Shielding Material Options:Shielding Material Options:

water, paper, plastic, cardboard, water, paper, plastic, cardboard, glass, ceramic tiles, aluminum foil, glass, ceramic tiles, aluminum foil, sheet coppersheet copper

Radioactivity Shielding LabRadioactivity Shielding Lab

What variables can we change?What variables can we change?

Distance?Distance?

Material? Material?

Thickness?Thickness?

Distance vs RadioactivityDistance vs Radioactivity11stst Trial Trial 22ndnd Trial Trial AverageAverage

BackgrounBackgroundd

1cm1cm

2cm2cm

3cm3cm

4cm4cm

5cm5cm

Shielding Material vs Shielding Material vs RadioactivityRadioactivity

Select 5 Select 5 MaterialsMaterials

11stst Trial Trial 22ndnd Trial Trial AverageAverage

Radioactivity Lab Directions (1 Radioactivity Lab Directions (1 of 2)of 2)

As a lab group:As a lab group:Part A: Investigate the effect of distance on Part A: Investigate the effect of distance on

radioactivity over at least 5 different levels.radioactivity over at least 5 different levels.1.1. Write an “if, then” hypothesis.Write an “if, then” hypothesis.2.2. Write a reason for your hypothesis.Write a reason for your hypothesis.

Part B: Investigate the effect of a shielding Part B: Investigate the effect of a shielding material on radioactivity.material on radioactivity.

1.1. Choose your unique material to vary over at Choose your unique material to vary over at least 5 different levels.least 5 different levels.

2.2. Write an “If, then” hypothesis. Write an “If, then” hypothesis. 3.3. Write a reason for your hypothesis.Write a reason for your hypothesis.4.4. Use distances that produce as large of counts Use distances that produce as large of counts

as countable.as countable.

Safety Guidelines:Safety Guidelines:

1.1. Always keep sample in lead box.Always keep sample in lead box.

2.2. Always face opening towards the Always face opening towards the wall.wall.

3.3. Rotate counters to minimize Rotate counters to minimize exposure. exposure.

Lab RequirementsLab Requirements

• Determine the background radiationDetermine the background radiation

• Use as our baselines the highest Use as our baselines the highest countable radioactivity possible. countable radioactivity possible.

• At least 5 different levels for each At least 5 different levels for each experiment.experiment.

Controlled VariablesControlled Variables

Distance Distance

• same equipment, same equipment,

• distance distance increments, increments,

• time, time,

• Positions & anglesPositions & angles

Shielding Shielding

• same shielding same shielding material, material,

• distance, distance,

• material additions, material additions,

• timetime

How Organize your Data How Organize your Data Table?Table?

Required Elements:Required Elements:

• Level – distance or shieldingLevel – distance or shielding

• Trial – 1Trial – 1stst, 2, 2ndnd, or 3, or 3rdrd repetition repetition

• Counts – per minute (or variation)Counts – per minute (or variation)

• Observations – things you notice and Observations – things you notice and record verbally like sources of error.record verbally like sources of error.

Finish Geiger Lab – Due Finish Geiger Lab – Due FridayFriday

Pick Your Roles & Rock & Roll:Pick Your Roles & Rock & Roll:Safety officerSafety officer

Set up experiments – Control distance?Set up experiments – Control distance?Count clicksCount clicks

Time experiments.Time experiments.Record dataRecord data

Calculate averagesCalculate averagesMake Excel graphMake Excel graph

Powerpoint lab report – start now.Powerpoint lab report – start now.PresentationPresentation

Recommendations for Recommendations for Minimizing Radiation ExposureMinimizing Radiation Exposure

Based on the findings of the class, what do you Based on the findings of the class, what do you recommend that manufacturers use to most recommend that manufacturers use to most efficiently and effectively protect patients and efficiently and effectively protect patients and employees from unnecessary exposure to employees from unnecessary exposure to radioactive diagnostic equipment? Write your radioactive diagnostic equipment? Write your recommendation in full sentences. Mention at recommendation in full sentences. Mention at least 2 factors. least 2 factors.

XC How could we test to see if radioactivity XC How could we test to see if radioactivity reflects off of the material used. Diagram the reflects off of the material used. Diagram the set up.set up.

Side 10 - Chapter 2 – Ancient Cultures Side 10 - Chapter 2 – Ancient Cultures – Archaeology – C14 Dating– Archaeology – C14 Dating

Side 10 – PET Scan – Positrons – ½ Side 10 – PET Scan – Positrons – ½ liveslives

Gamma raysGamma rays

Geiger Lab RubricGeiger Lab RubricPresentatioPresentation Skillsn Skills

Points made Points made clearly & clearly & conciselyconcisely

Summarizing Summarizing information information clearly.clearly.

SummarizinSummarizing, but g, but lacking lacking clarity.clarity.

Reading to Reading to audience, audience, lacking eye lacking eye contact or contact or loud voices.loud voices.

ExperimentExperimental Designal Design

All external All external influences influences controlled controlled as well.as well.

Internal Internal variables of variables of experiment experiment controlledcontrolled

Lacking Lacking controls on controls on internal internal variables.variables.

Clear Clear independent independent & & dependent dependent variable.variable.

Data & Data & ObservatioObservationsns

Complete Complete set of set of multiple multiple (>2) trials.(>2) trials.

Complete set Complete set of 2 trials for of 2 trials for each each experiment.experiment.

One One complete complete set of trials.set of trials.

Data Data missing missing from report.from report.

ConclusionsConclusions Accurately Accurately interprets interprets results & results & applies to applies to life.life.

Uses Uses experimental experimental evidenceevidence

Compares Compares results.results.

Revisits Revisits hypothesishypothesis

IsotopesIsotopes• Atoms of a single element have the same Atoms of a single element have the same

number of protons but may differ in number of protons but may differ in neutrons.neutrons.

• Example 1: Carbon-12 vs Carbon-14Example 1: Carbon-12 vs Carbon-14

• Example 2: Uranium-238 vs Uranium-235Example 2: Uranium-238 vs Uranium-235

• Some isotopes are stable while others are Some isotopes are stable while others are unstable and radioactive.unstable and radioactive.

• The STRONG NUCLEAR FORCE acts The STRONG NUCLEAR FORCE acts between protons & neutrons to hold them between protons & neutrons to hold them together. However protons will repel each together. However protons will repel each other with their mutual positive charge. other with their mutual positive charge.

Carbon IsotopesCarbon IsotopesIsotopeIsotope Half – lifeHalf – life

Carbon – 9Carbon – 9 0.1265 s0.1265 s

Carbon – Carbon – 10 10

19.2 s19.2 s

Carbon – Carbon – 1111

20.38 20.38 minmin


StableStable


StableStable


5715 y5715 y

Carbon – Carbon – 15 15

2.449 s2.449 s


0.75 s0.75 s

• How long does it How long does it take 400 g of each take 400 g of each isotope to decay to isotope to decay to less than 1 mg?less than 1 mg?

Beanium – Average Atomic Mass Beanium – Average Atomic Mass ActivityActivity

7. Find the average mass of each of the 3 7. Find the average mass of each of the 3 beanium isotopes.beanium isotopes.

Average mass of ___ beans = subtotal Average mass of ___ beans = subtotal mass/#of beansmass/#of beans

8. % Abundance of each type = 8. % Abundance of each type =

# of beans/total beans (x100 to make a %)# of beans/total beans (x100 to make a %)

10. Average beanium atomic mass10. Average beanium atomic mass

= (%white x avg mass white) = (%white x avg mass white)

+ (%black x avg black mass) + (%black x avg black mass)

+ (%red x avg red mass)+ (%red x avg red mass)

*Convert the %s back into decimals to do *Convert the %s back into decimals to do #10.#10.

Nuclear ReactionsNuclear Reactions• Radioactivity results from changes in Radioactivity results from changes in

atomic nuclei. atomic nuclei.

• Fission – splitting of a large nucleus into Fission – splitting of a large nucleus into smaller pieces releases energy. smaller pieces releases energy.

• Fusion – small nuclei join to make a larger Fusion – small nuclei join to make a larger nucleus and release energy. (PS1, Ch25)nucleus and release energy. (PS1, Ch25)

• Energy is released when a small amount Energy is released when a small amount of mass converts to energy as E = mcof mass converts to energy as E = mc22..

Fusion of Hydrogen IsotopesFusion of Hydrogen Isotopes• At high At high

temperatures and temperatures and pressures, 2 nuclei pressures, 2 nuclei may collide and form may collide and form a bigger nucleus.a bigger nucleus.

• This example This example produces helium and produces helium and a stray neutron.a stray neutron.

• Stars are fueled by Stars are fueled by the energy released the energy released by fusion which also by fusion which also builds atoms of builds atoms of increasing sizes in increasing sizes in their cores.their cores.

Fission of UraniumFission of Uranium• A neutron splits the

nucleus.

• The fragments include:– 2 different smaller

atoms,– 3 more neutrons.

• The 3 neutrons can split more atoms.

• If every fission splits 3 more atoms, the reaction will multiply out of control!

Nuclear Nuclear Chain Chain ReactionReaction

Nuclear WarheadsNuclear Warheads

Chernobyl Nuclear DisasterChernobyl Nuclear Disaster

Nuclear EquationsNuclear Equations• Alpha (Alpha () Decay – releases 2 protons ) Decay – releases 2 protons

& 2 neutrons - a helium nucleus.& 2 neutrons - a helium nucleus.

• Beta (Beta () Decay – a neutron converts ) Decay – a neutron converts to a proton and releases an electron.to a proton and releases an electron.

4 He2

0 e-1

Nuclear EquationsNuclear Equations• Uranium 238 does alpha decay:Uranium 238 does alpha decay:

– Mass numbers balance on both sides.Mass numbers balance on both sides.– Atomic numbers balance on both sidesAtomic numbers balance on both sides

• Thorium 234 then does beta decay:Thorium 234 then does beta decay:

4 He2

238 U

92

234 Th

90+

234 Th

90

0 e-1

234 Pa

91+

Nuclear Equations ProblemsNuclear Equations Problems1.1. U–238 does alpha decay in nuclear reactors.U–238 does alpha decay in nuclear reactors.

2.2. Am-241 does alpha decay in smoke alarms.Am-241 does alpha decay in smoke alarms.

3.3. Tc-99 does beta decay in medical exams.Tc-99 does beta decay in medical exams.

4.4. C–14 does beta decay in carbon dating.C–14 does beta decay in carbon dating.

5.5. The Curies used Ra-226 which does alpha The Curies used Ra-226 which does alpha decay.decay.

6.6. Co–60 does beta decay in food irradiation.Co–60 does beta decay in food irradiation.

7.7. Th-232 does alpha decay in camp lanterns.Th-232 does alpha decay in camp lanterns.

8.8. P-35 does beta decay in DNA studiesP-35 does beta decay in DNA studies

Uranium Decay SeriesUranium Decay Series• U238 alpha - HL U238 alpha - HL

4.468e9y4.468e9y• Th234 beta – HL 24.10dTh234 beta – HL 24.10d• Pa234 beta – HL 6.70hPa234 beta – HL 6.70h• U234 alpha – HL U234 alpha – HL

245,500y245,500y• Th230 alpha – HL Th230 alpha – HL

75,380y75,380y• Ra226 alpha – HL1600yRa226 alpha – HL1600y• Rn222 alpha – HL Rn222 alpha – HL

3.8325d3.8325d

• Po218 alpha – HL Po218 alpha – HL 3.10m3.10m

• Pb214 beta – HL 26.8mPb214 beta – HL 26.8m• Bi214 beta – HL 19.9mBi214 beta – HL 19.9m• Po214 alpha – HL 164.3 Po214 alpha – HL 164.3

ss• Pb210 beta – HL 22.6yPb210 beta – HL 22.6y• Bi210 beta – HL 138dBi210 beta – HL 138d• Po210 alpha – HL Po210 alpha – HL

4.199m4.199m• Pb206 Stable!Pb206 Stable!

Nuclear Equations QuizNuclear Equations Quiz

1.1.Write the nuclear equation Write the nuclear equation for the alpha decay of for the alpha decay of Iodine 131.Iodine 131.

2.2.Write the nuclear equation Write the nuclear equation for the beta decay of for the beta decay of cobalt 60.cobalt 60.

½ Lives Activity½ Lives Activity• Obtain a set of “radioactive” blocks. Notice that each one Obtain a set of “radioactive” blocks. Notice that each one

has a mark on one side – either a, b or g. has a mark on one side – either a, b or g.

• Roll the collection of blocks onto your table. Each time Roll the collection of blocks onto your table. Each time you roll, remove any blocks that come up you roll, remove any blocks that come up , , or or . .

• Count and record the remaining blocks. Roll the Count and record the remaining blocks. Roll the remaining blocks repeatedly 20 times and complete the remaining blocks repeatedly 20 times and complete the chart below.chart below.

• Enter your group data into the Enter your group data into the excel file..

• Make graphs of Time(minutes) Remaining Atoms for both Make graphs of Time(minutes) Remaining Atoms for both individual & class averages. **Use “exponential” rather individual & class averages. **Use “exponential” rather than “linear” trendlines.than “linear” trendlines.

RollRoll

(minutes)(minutes)Remaining Remaining AtomsAtoms

Class Class AverageAverage

½ Lives Activity Questions½ Lives Activity Questions

1.1. How do your lab pair results compare How do your lab pair results compare with the class average results?with the class average results?

2.2. Use the class average results and Use the class average results and compute the 1compute the 1stst ½ life, 2 ½ life, 2ndnd ½ life, ½ life, average ½ life.average ½ life.

3.3. What importance do ½ lives have to What importance do ½ lives have to society? society?

(dating, medical uses, wastes)(dating, medical uses, wastes)

½ Lives½ Lives• Each radio-isotope decays at a characteristic Each radio-isotope decays at a characteristic

rate.rate.• The decay rate is determined by the time that The decay rate is determined by the time that

it takes for ½ of the radio-isotope nuclei to it takes for ½ of the radio-isotope nuclei to break down by fission.break down by fission.

• Each ½ life reduces the remaining number of Each ½ life reduces the remaining number of radioactive atoms by ½. radioactive atoms by ½.

• The number remaining approaches but never The number remaining approaches but never reaches zero.reaches zero.

• Example: Iodine 131 has a ½ life of 8 days. Example: Iodine 131 has a ½ life of 8 days. How much of 1.00 gram sample would remain How much of 1.00 gram sample would remain after 24 days?after 24 days?

Solving ½ Life ProblemsSolving ½ Life Problems

Masses:Masses:

• STARTING STARTING MASSMASS

• Divided in ½ Divided in ½ the # of half the # of half lives.lives.

• ending massending mass

Times:Times:

• Time for 1 Time for 1 half life (HL)half life (HL)

• Total time Total time elapsed (T)elapsed (T)

• T = HL*(#)T = HL*(#)

• HL = T/#HL = T/#

• # = T/HL# = T/HL

# of halflives

½ Life Example 1 – Iodine 131 has a ½ ½ Life Example 1 – Iodine 131 has a ½ life of 8 days. How much of 1.00 gram life of 8 days. How much of 1.00 gram sample would remain after 24 days? sample would remain after 24 days?

Times:Times:

½ life = 8 days½ life = 8 days

Total = 24 daysTotal = 24 days

24days / 8days 24days / 8days

= 3 half lives= 3 half lives

Masses: Masses:

Start = 1.00 gStart = 1.00 g

End = ?unknownEnd = ?unknown

If 3 half lives occur,If 3 half lives occur,

divide start by 2 3-divide start by 2 3-timestimes

1.00 g / 2 / 2 / 2 1.00 g / 2 / 2 / 2

= .125 g= .125 g

½ Life Example 2: A 8.8mg sample of ½ Life Example 2: A 8.8mg sample of chromium-55 is analyzed after 15 min chromium-55 is analyzed after 15 min and found to contain 1.1mg and found to contain 1.1mg remaining. What is the ½ life of Cr55?remaining. What is the ½ life of Cr55?

Masses:Masses:

Start = 8.8 mgStart = 8.8 mg

End = 1.1mgEnd = 1.1mg

Divide 4.4 by 2 until Divide 4.4 by 2 until reaching 1.1.reaching 1.1.

8.8/2 = 4.48.8/2 = 4.4

4.4/2 = 2.24.4/2 = 2.2

2.2/2 = 1.12.2/2 = 1.1

3 – ½ lives occurred3 – ½ lives occurred

Times:Times:

Total = 15 minTotal = 15 min

½ life = ? Unknown½ life = ? Unknown

Divide 15 min by 3 – ½ Divide 15 min by 3 – ½ liveslives

15min/3 HL15min/3 HL

= 5 min/1HL= 5 min/1HL

5 min = 1 – ½ life5 min = 1 – ½ life

½ Life Problems½ Life Problems1.1. If you have $1 million dollars and every 2 If you have $1 million dollars and every 2

seconds it decreases by 1/2, how long seconds it decreases by 1/2, how long will it take until you are penniless?will it take until you are penniless?

2.2. If a sample of a fossil mammoth has 1/8If a sample of a fossil mammoth has 1/8thth the amount of carbon 14 as it would the amount of carbon 14 as it would today, how old must the fossil be? (1/2L today, how old must the fossil be? (1/2L C14 = 5715 years.C14 = 5715 years.

3.3. If a rock contained 1.2 g of potassium 40 If a rock contained 1.2 g of potassium 40 when it formed, how many grams remain when it formed, how many grams remain after 4 billion years. (1/2L K40 = 1.33E9 after 4 billion years. (1/2L K40 = 1.33E9 y)y)

Asmt: P780 #1&2, P803 #24&25Asmt: P780 #1&2, P803 #24&25

More ½ Life ProblemsMore ½ Life Problems4. If a sample of radioactive isotope has a half-life of 4. If a sample of radioactive isotope has a half-life of

1 year, how much of the original sample will be 1 year, how much of the original sample will be left at the end of the second year? The third left at the end of the second year? The third year? The fourth year?year? The fourth year?

5. The isotope cesium-137, which has a half-life of 5. The isotope cesium-137, which has a half-life of 30 years, is a product of nuclear power plants. 30 years, is a product of nuclear power plants. How long will it take for this isotope to decay to How long will it take for this isotope to decay to about one-sixteenth its original amount?about one-sixteenth its original amount?

6.6. Iodine-131 has a half-life of 8 days. What fraction Iodine-131 has a half-life of 8 days. What fraction of the original sample would remain at the end of of the original sample would remain at the end of 32 days?32 days?

7.7. The half-life of chromium-51 is 28 days. If the The half-life of chromium-51 is 28 days. If the sample contained 510 grams, how much sample contained 510 grams, how much chromium would remain after 56 days? How chromium would remain after 56 days? How much would remain after 1 year?much would remain after 1 year?

½ Lives Quiz½ Lives Quiz

1. A sample of a radioactive isotope with an 1. A sample of a radioactive isotope with an original mass of 8.00g is observed for 30 original mass of 8.00g is observed for 30 days. After that time, 0.25g of the isotope days. After that time, 0.25g of the isotope remains. What is its half-life?remains. What is its half-life?

2. The starting mass of a radioactive isotope 2. The starting mass of a radioactive isotope is 20.0g. The half-life period of this isotope is 20.0g. The half-life period of this isotope is 2 days. The sample is observed for 14 is 2 days. The sample is observed for 14 days. What PERCENTAGE of the original days. What PERCENTAGE of the original amount remains after 14 days?amount remains after 14 days?

Health Physics SocietyHealth Physics Society

• http://hps.org/publicinformation/ate/q754.html

• Q:Q:What are some health effects of the element uranium?What are some health effects of the element uranium?

• A:A:The toxicity of uranium has been under study for over 50 years, The toxicity of uranium has been under study for over 50 years, including life-span studies in small animals. Depleted uranium and including life-span studies in small animals. Depleted uranium and natural uranium both consist primarily of the uranium isotope natural uranium both consist primarily of the uranium isotope 238U. They are only very weakly radioactive and are not hazardous 238U. They are only very weakly radioactive and are not hazardous radioactive toxicants, but uranium is a weak chemical poison that radioactive toxicants, but uranium is a weak chemical poison that can seriously damage the kidneys at high blood concentrations. can seriously damage the kidneys at high blood concentrations. Virtually all of the observed or expected effects are from Virtually all of the observed or expected effects are from nephrotoxicity associated with deposition in the kidney tubules and nephrotoxicity associated with deposition in the kidney tubules and glomeruli damage at high blood concentrations of uranium. The glomeruli damage at high blood concentrations of uranium. The ionizing radiation doses from depleted and natural uranium are ionizing radiation doses from depleted and natural uranium are very small compared to potential toxic effects from uranium ions in very small compared to potential toxic effects from uranium ions in the body (primarily damage to kidney tubules). the body (primarily damage to kidney tubules).

http://hps.org/publicinformation/ate/q754.html

Modern Atomic TheoryModern Atomic Theory

Quantum Mechanical ModelQuantum Mechanical Model

(Electron Cloud Model)(Electron Cloud Model)

Electrons & Standing WavesElectrons & Standing Waves

1.1. Electrons don’t move in straight lines; Electrons don’t move in straight lines; they move as waves.they move as waves.

2.2. Electron microscopes allow us to see Electron microscopes allow us to see flies eyes since electron wavelengths flies eyes since electron wavelengths are shorter than visible light waves.are shorter than visible light waves.

3.3. Electrons orbiting a positive nucleus Electrons orbiting a positive nucleus settle into low energy standing wavessettle into low energy standing waves

4.4. Demo – Standing wavesDemo – Standing waves

OrbitalsOrbitals

1. Electron wave orbits 1. Electron wave orbits are too complicated to are too complicated to track.track.

2.2. Chemists describe Chemists describe their probable location their probable location as clouds.as clouds.

3.3. Orbitals are defined as Orbitals are defined as the space they occupy the space they occupy 90% of the time.90% of the time.

4.4. Demo: Electrons Demo: Electrons occupy orbitals like occupy orbitals like fan bladesfan blades

Orbital DemosOrbital Demos

1.1. Electrons move so fast they occupy Electrons move so fast they occupy space like fan blades!space like fan blades!

2.2. The most stable patterns for electron The most stable patterns for electron wave motions are standing waves!wave motions are standing waves!

3.3. *Electrons move fastest passing the *Electrons move fastest passing the nucleus and spend little time there.nucleus and spend little time there.

http://galileoandeinstein.physics.virginia.edu/more_stuff/flashlets/Slingshot.htm

1.1. Orbital DiagramsOrbital Diagrams

2.2. Video – CheMedia Side 2, Chapter 23Video – CheMedia Side 2, Chapter 23



F orbitalsF orbitals

• Start at the fourth energy levelStart at the fourth energy level• Have seven different shapesHave seven different shapes• 2 electrons per shape for a total of 14 2 electrons per shape for a total of 14

electrons.electrons.

F orbitalsF orbitals

Electron OrbitalsElectron Orbitals

Level 4Level 4778 Lobed8 LobedFF

Level 3Level 355CloverleafCloverleafDD

Level 2Level 233Dumb-bellDumb-bellPP

Level 1Level 111SphericalSphericalSS

11stst Occur OccurSetSetShapeShapeTypeType

Electron ConfigurationsElectron Configurations

• Orbitals can hold 2 electrons each.Orbitals can hold 2 electrons each.

• Lowest energy orbitals fill first.Lowest energy orbitals fill first.

• Electrons repel and occupy separate Electrons repel and occupy separate orbitals on the same energy level if orbitals on the same energy level if possible.possible.

• Orbital Packing Key:Orbital Packing Key:

• 1s1s222s2s222p2p663s3s223p3p664s4s223d3d10104p4p665s5s224d4d10105p5p66…….…….

• Animated Electron ConfigurationsAnimated Electron Configurations

Orbital filling tableOrbital filling table

http://upload.wikimedia.org/wikipedia/commons/a/a1/Electron_Configuration_Table.jpg

Electron Configurations vs Electron Configurations vs PicturesPictures

1 H

+-

1s1


1 H

+-

1s1

2 He 1s2

-+


1 H

+-

1s1

2 He 1s2

+ -

3 Li 1s22s1

-

+


1 H

+-

1s1

2 He 1s2

+ -

3 Li 1s22s1

-

4 Be 1s22s2

-

++


1 H

+-

1s1

2 He 1s2

+ -

3 Li 1s22s1

-

4 Be 1s22s2

-

++

5 B 1s22s22p1

-

+


1 H

+-

1s1

2 He 1s2

+ -

3 Li 1s22s1

-

4 Be 1s22s2

-

+

5 B 1s22s22p1

-

+

6 C 1s22s22p2

-+

+


1 H

+-

1s1

2 He 1s2

+ -

3 Li 1s22s1

-

4 Be 1s22s2

-

++

5 B 1s22s22p1

-

+

6 C 1s22s22p2

-+

+

7N 1s22s22p3

-


1 H

+-

1s1

2 He 1s2

+ -

3 Li 1s22s1

-

4 Be 1s22s2

-

++

5 B 1s22s22p1

-

+

6 C 1s22s22p2

-+

+

7N 1s22s22p3

-

+

8O 1s22s22p4

-


1 H

+-

1s1

2 He 1s2

+ -

3 Li 1s22s1

-

4 Be 1s22s2

-

++

5 B 1s22s22p1

-

+

6 C 1s22s22p2

-+

+

7N 1s22s22p3

-

+

8O 1s22s22p4

-9F 1s22s22p5

-


1 H

+-

1s1

2 He 1s2

+ -

3 Li 1s22s1

-

4 Be 1s22s2

-

++

5 B 1s22s22p1

-

+

6 C 1s22s22p2

-+

+

7N 1s22s22p3

-

+

8O 1s22s22p4

-9F 1s22s22p5

-

10Ne 1s22s22p6+

-


1 H

+-

1s1

2 He 1s2

+ -

3 Li 1s22s1

-

4 Be 1s22s2

-

++

5 B 1s22s22p1

-

+

6 C 1s22s22p2

-+

+

7N 1s22s22p3

-

+

8O 1s22s22p4

-9F 1s22s22p5

-

10Ne 1s22s22p6+

-

-

11Na

1s22s22p63s1

--

-

--

-

-

--

-


+++

+

+++++

-

Examples:Examples:

1.1. Write the electron configuration & Write the electron configuration & draw an atom of fluorine.draw an atom of fluorine.

Asmt: Write electron configurations of Asmt: Write electron configurations of elements 1,5,9,13,17,21,25,29.elements 1,5,9,13,17,21,25,29.

Electron Configurations Quiz Electron Configurations Quiz 111.1. Write the full electron configuration & Write the full electron configuration &

draw the atom for nitrogen, N – atomic draw the atom for nitrogen, N – atomic number 7, atomic mass 14.01.number 7, atomic mass 14.01.

2.2. Write the full & Noble Gas electron Write the full & Noble Gas electron configurations for nickel, Ni – atomic configurations for nickel, Ni – atomic number 28.number 28.

3.3. Identify the element with the Noble Gas Identify the element with the Noble Gas electron configuration of [Ar]4selectron configuration of [Ar]4s223d3d66. . Explain how you know.Explain how you know.

Photoelectric Effect & Solar Photoelectric Effect & Solar EnergyEnergy

•http://www.walter-fendt.de/ph14e/photoeffect.htm

•http://phet.colorado.edu/new/simulations/sims.php?sim=Photoelectric_Effect

•http://www1.eere.energy.gov/solar/photoelectric_effect.html

•http://www.electronsolarenergy.com/resources.htm

http://www.walter-fendt.de/ph14e/photoeffect.htm

http://www.walter-fendt.de/ph14e/photoeffect.htm

http://phet.colorado.edu/new/simulations/sims.php?sim=Photoelectric_Effect



http://www1.eere.energy.gov/solar/photoelectric_effect.html

http://www1.eere.energy.gov/solar/photoelectric_effect.html

http://www.electronsolarenergy.com/resources.htm

http://www.electronsolarenergy.com/resources.htm

Tuesday 11/27/07Tuesday 11/27/07Prep:Prep:1.1. See Neil about Periodic Table ActivitiesSee Neil about Periodic Table Activities2.2. Determine Periodic Table book assignmentDetermine Periodic Table book assignmentClass:Class:Periods 1 & 3Periods 1 & 3DMA: What element corresponds to the configuration DMA: What element corresponds to the configuration

[Kr]5s[Kr]5s224d4d10105p5p55??1.1. Take & correct quizTake & correct quiz2.2. Periodic Table ActivityPeriodic Table ActivityAsmt: Page 163 #1-4, page 173 #1,3, page 185 #2Asmt: Page 163 #1-4, page 173 #1,3, page 185 #2Plan: Meet with PODPlan: Meet with PODPeriods 4-6Periods 4-6Library Utopia ProjectLibrary Utopia ProjectAfterschool:Afterschool:1.1. Grade Poster ProjectsGrade Poster Projects2.2. Contact National Boards about appeal of Active InquiryContact National Boards about appeal of Active Inquiry3.3. Go to Wells FargoGo to Wells Fargo

1.1. Deposit checks, get new registers!Deposit checks, get new registers!2.2. Provide mortgage documentsProvide mortgage documents

Orbital AnimationsOrbital Animations

• Chemedia Laserdisc Demo – Side 2, Chemedia Laserdisc Demo – Side 2, Chapter 23Chapter 23

• http://www.colby.edu/chemistry/http://www.colby.edu/chemistry/OChem/DEMOS/Orbitals.htmlOChem/DEMOS/Orbitals.html

Electron Configurations Quiz Electron Configurations Quiz 22

1.1. Write the electron configuration & Write the electron configuration & draw an atom of oxygen.draw an atom of oxygen.

2.2. Write the complete and Noble Gas Write the complete and Noble Gas configurations for arsenic, As.configurations for arsenic, As.

3.3. Identify the element that Identify the element that approximately matches approximately matches [Xe]6s[Xe]6s225d5d10104f4f14146p6p22 & explain how & explain how you know.you know.

Periodic Table ActivityPeriodic Table Activity

Thursday 11/29/07Thursday 11/29/07Prep:Prep:1. Grade fireworks posters.1. Grade fireworks posters.Class:Class:P1-3P1-3DMA: What principle determines which elements are in the same vertical column?DMA: What principle determines which elements are in the same vertical column?Due: Page 163,173,185, Fill in blanks?Due: Page 163,173,185, Fill in blanks?1.1. Fill in blanks Periodic Table, 1 part at a timeFill in blanks Periodic Table, 1 part at a time2.2. Notes on Development of Periodic TableNotes on Development of Periodic TableAsmt: Shade sections of 9 overlapping sections of Periodic Table (pages 164-7)Asmt: Shade sections of 9 overlapping sections of Periodic Table (pages 164-7)Plan: Plan: 1.1. Finalize POD meeting plans & Sliding Scenario pieces.Finalize POD meeting plans & Sliding Scenario pieces.2.2. Grade Fireworks posters.Grade Fireworks posters.P4-6P4-6DMA: Electron Configurations Quiz 2DMA: Electron Configurations Quiz 21.1. Grade QuizGrade Quiz2.2. Periodic Table Card PuzzlePeriodic Table Card PuzzleAsmt: Asmt: Shade sections of 9 overlapping sections of Periodic Table (pages 164-Asmt: Asmt: Shade sections of 9 overlapping sections of Periodic Table (pages 164-

7)7)After School:After School:1.1. Grade fireworks postersGrade fireworks posters2.2. Thursday chores at home plus piano practicing.Thursday chores at home plus piano practicing.3.3. Left overs, chips to Men’s group.Left overs, chips to Men’s group.

Development of the Periodic Table (1 Development of the Periodic Table (1 of 2)of 2)• Periodic Law – When elements are Periodic Law – When elements are

arranged in increasing atomic arranged in increasing atomic number, their chemical & physical number, their chemical & physical properties show a periodic pattern.properties show a periodic pattern.

• Dobereiner grouped the elements Dobereiner grouped the elements into triads with similar chemical into triads with similar chemical properties.properties.

• Newlands arranged the elements by Newlands arranged the elements by increasing atomic mass and increasing atomic mass and observed the Law of Octaves where observed the Law of Octaves where elements of similar properties elements of similar properties occurred every 8occurred every 8thth element. element.

Development of the Periodic Table (2 Development of the Periodic Table (2 of 2)of 2)• Mendeleev arranged the elements by Mendeleev arranged the elements by

increasing mass & similar properties in increasing mass & similar properties in 1872.1872.

• Mendeleev suggested that atomic masses Mendeleev suggested that atomic masses that were out of line with the similar that were out of line with the similar properties needed to be remeasured.properties needed to be remeasured.

• Mendeleev accurately predicted the Mendeleev accurately predicted the existence and properties of elements yet to existence and properties of elements yet to be discovered.be discovered.

• Moseley discovered a pattern in the spectral Moseley discovered a pattern in the spectral lines of elements which corresponded to the lines of elements which corresponded to the atomic number and number of protons.atomic number and number of protons.

Periodic Table PatternsPeriodic Table Patterns

•http://www.sciencebyjones.com/periodic_table1.htm

•http://environmentalchemistry.com/yogi/periodic/#Chemical%20elements%20sorted%20by

• Can use the one above to find the Can use the one above to find the patterns & then explain them.patterns & then explain them.

http://www.sciencebyjones.com/periodic_table1.htm

http://www.sciencebyjones.com/periodic_table1.htm

http://environmentalchemistry.com/yogi/periodic/#Chemical%20elements%20sorted%20by



Observing Element SamplesObserving Element Samples

1. Use your blank periodic table with 1. Use your blank periodic table with trends of electron configurations.trends of electron configurations.

2.2. Observe 2 samples from each of the Observe 2 samples from each of the 9 sets around the room.9 sets around the room.

3.3. For each sample, record the symbol For each sample, record the symbol in the correct box plus 2 words to in the correct box plus 2 words to describe the appearance of the describe the appearance of the sample.sample.

Monday 12/2/07Monday 12/2/07

• Periodic trends – atomic radius, Periodic trends – atomic radius, ionization energy, electronegativityionization energy, electronegativity

• Analyze data & graphs, Explain Analyze data & graphs, Explain trendstrends

Patterns of Electron Patterns of Electron ConfigurationsConfigurations

Vertical PatternsVertical Patterns Horizontal PatternsHorizontal Patterns

Same number and Same number and type of valence type of valence electrons.electrons.

Same kernel acrossSame kernel across

Energy level rises for Energy level rises for each row.each row.

The kernel is the The kernel is the previous noble gasprevious noble gas

Highest energy level Highest energy level is the same across a is the same across a row.row.

Patterns of Electron Patterns of Electron ConfigurationsConfigurations

• Vertical PatternsVertical Patterns

• Same number and Same number and type of valence type of valence electrons.electrons.

• Energy level rises Energy level rises for each row.for each row.

• Horizontal PatternsHorizontal Patterns

• Same kernel acrossSame kernel across

• The kernel is the The kernel is the previous noble gasprevious noble gas

• Highest energy Highest energy level is the same level is the same across a row.across a row.

Periodic PatternsPeriodic Patterns

[x] [:x:]:

:

:: . .O

::: :Ne

: :. .X

H.

X. Be:X:

X: .

Al.

: C:. .

. .X:

:. ..N

. . .

:X

: :.F:

X

::: ::: .X

:He:

[:x:]

::[:x:]:

:[x] [x]+4-4

+1 +2 +3 -3 -2 -1

s1

s2 s2p1 s2p2 s2p3 s2p4 s2p5

s2p6

Ion formation: Loss (oxidation) or gain (reduction) of electrons

Periodic TrendsPeriodic Trends

• Trends in atomic radius, ionization energy, Trends in atomic radius, ionization energy, & electronegativity are determined by:& electronegativity are determined by:

• The number of energy levels present.The number of energy levels present.• The attraction between the positive The attraction between the positive

nucleus and the outer shell electrons.nucleus and the outer shell electrons.• Interfering “shielding” by electrons on Interfering “shielding” by electrons on

inner shells.inner shells.• How close an atom is to completing the How close an atom is to completing the

stable octet of outer “valence” electrons.stable octet of outer “valence” electrons.

Atomic Radius (1 of 3)Atomic Radius (1 of 3)

• Alkali metals are the largest atoms. Alkali metals are the largest atoms.

• Noble gases are the smallest atoms.Noble gases are the smallest atoms.

Atomic Radius (2 of 3)Atomic Radius (2 of 3)

Atomic radius Atomic radius trends:trends:

1)1) Atomic radius Atomic radius increases increases down a group down a group or column.or column.

2)2) Atomic radius Atomic radius decreases decreases across a across a period or row.period or row.

Atomic Radius (3 of 3)Atomic Radius (3 of 3)How do we explain the trends?How do we explain the trends?

1.1. Atomic radius increases down a group:Atomic radius increases down a group:• Each row adds an energy level.Each row adds an energy level.• Interior electrons interfere with attraction of Interior electrons interfere with attraction of

valence electrons toward the nucleus “shielding valence electrons toward the nucleus “shielding effect”effect”

2.2. Atomic radius decreases across a row even Atomic radius decreases across a row even while the atomic number increases:while the atomic number increases:

• While in the same energy level, the nucleus While in the same energy level, the nucleus becomes more positive & attractive.becomes more positive & attractive.

• Ionization – Removal of electrons produces Ionization – Removal of electrons produces + charges & shrinks radius.+ charges & shrinks radius.

• http://hogan.chem.lsu.edu/matter/chap26/animate2/an26_017.mov

• Animated Ionizations Change Radii Across Animated Ionizations Change Radii Across periodic table.periodic table.

• http://www.chem.iastate.edu/group/http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/Greenbowe/sections/projectfolder/flashfiles/matters/periodicTbl2.htmlflashfiles/matters/periodicTbl2.html

http://hogan.chem.lsu.edu/matter/chap26/animate2/an26_017.mov

http://hogan.chem.lsu.edu/matter/chap26/animate2/an26_017.mov

Ionization Energy (1 of 4)Ionization Energy (1 of 4)• Ionization energy Ionization energy

is the energy is the energy required to required to remove a negative remove a negative electron and leave electron and leave an atom with a an atom with a positive charge – positive charge – as an ion.as an ion.

• Occurs in solar Occurs in solar cells, geiger cells, geiger counters & smoke counters & smoke detectors with detectors with Amerecium 241Amerecium 241

Ionization Energy (2 of 4)Ionization Energy (2 of 4)

• Alkali metals lose their electrons most easily.Alkali metals lose their electrons most easily.

• Noble gases hold their electrons most tightly.Noble gases hold their electrons most tightly.


• Removing an Removing an electron electron becomes becomes more difficult more difficult across a row.across a row.

• Removing Removing electrons electrons becomes becomes easier down a easier down a column.column.


• Removing electrons is more difficult across a Removing electrons is more difficult across a row as the nuclear attractions become row as the nuclear attractions become stronger.stronger.

• Removing electrons is easier down a column Removing electrons is easier down a column as each additional energy level increases the as each additional energy level increases the distance from the nucleus and weakens the distance from the nucleus and weakens the nuclear attraction. nuclear attraction.

• Repulsive shielding by interior electrons also Repulsive shielding by interior electrons also decreases the attraction for each added decreases the attraction for each added level.level.

Electronegativity (1 of 3)Electronegativity (1 of 3)

• Electro-Electro-negativity negativity is the is the ability of ability of an atom to an atom to attract attract electrons electrons that are that are shared in a shared in a covalent covalent bond.bond.

Equal Sharing

Unequal Sharing

H2

HCl

2.1 2.1

2.13.5

Electrons hogged by Cl

Electronegativity (2 of 3)Electronegativity (2 of 3)• What are the trends in electronegativity?What are the trends in electronegativity?

Electronegativity (3 of 3)Electronegativity (3 of 3)• Electronegativity Electronegativity

increases up & increases up & to the right. to the right.

• This trend This trend corresponds to corresponds to stronger stronger attractions to attractions to the nucleus.the nucleus.

• Less shielding Less shielding effect effect strengthens strengthens attractions to attractions to the nucleus in the nucleus in upper rows.upper rows.

Periodic Patterns QuizPeriodic Patterns Quiz

1. Atomic Radius Question – a) What is 1. Atomic Radius Question – a) What is the size surprise? b) Why does it occur?the size surprise? b) Why does it occur?

2. Ionization Energy – Why are the lowest 2. Ionization Energy – Why are the lowest ionization energies in the bottom left?ionization energies in the bottom left?

3. Electronegativity – Arrange each set of 3. Electronegativity – Arrange each set of atoms in order from least to greatest atoms in order from least to greatest electronegativity: a) Mg, Ba, Sr; b) Cl, electronegativity: a) Mg, Ba, Sr; b) Cl, F, I; c) Fe, K, BrF, I; c) Fe, K, Br

Periodic Patterns of Periodic Patterns of ReactivityReactivity• Choose an element from the periodic Choose an element from the periodic

table.table.

• Predict how you think it will react with Predict how you think it will react with air, water, acids or bases.air, water, acids or bases.

• Observe the laserdisc video.Observe the laserdisc video.

• Record the reactivity on a 1R-10R scale.Record the reactivity on a 1R-10R scale.

• Examine no more than 3 per group.Examine no more than 3 per group.

• Identify patterns of reactivity.Identify patterns of reactivity.

Periodic Patterns of Periodic Patterns of ReactivityReactivity

Comparing Periodic GroupsComparing Periodic Groups

Noble Noble GasesGases

HalogensHalogens

OxygenOxygen

NitrogenNitrogen

CarbonCarbon

BoronBoron

TransitionTransition

Alkaline Alkaline EarthEarth

Na – table saltNa – table salt

K - gatoradeK - gatoradeElectrolyze Electrolyze

saltssaltsSoft metals,Soft metals,

Explode in H2OExplode in H2O+1+1SS11AlkaliAlkali

Uses of 2 Uses of 2 elements of elements of

GroupGroup

Sources of 2 – Sources of 2 – How obtainedHow obtained

PropertiesPropertiesCommon Common IonicIonic

Charges Charges

CommoCommonn

Valence Valence ElectronElectron

ss

GroupGroup

Comparing Periodic GroupsComparing Periodic GroupsGroupGroup ValenceValence

ssIons, Ions,

# of Bonds# of BondsPropertiesProperties Sources of 2 – Sources of 2 –

How obtainedHow obtainedUses of 2 Uses of 2 elements minelements min

AlkaliAlkali S1S1 +1, ionic+1, ionic Soft metals, Soft metals, explosiveexplosive

Electrolyze Electrolyze saltssalts

Na – table saltNa – table salt

K – gatoradeK – gatorade

Alkaline Alkaline EarthEarth

S2S2 +2, ionic+2, ionic Soft, highly Soft, highly reactivereactive


Ca – bones,Ca – bones,

Mg – flash bulbsMg – flash bulbs

TransitionTransition S2d1 – S2d1 – s2d10s2d10

Various Various chargescharges

+2,+3, +4 +2,+3, +4

Hard Hard metals, w/ metals, w/ varying varying resistanceresistance

Mined & Mined & extracted from extracted from oresores

Iron in steel,Iron in steel,

Gold jewelryGold jewelry

BoronBoron S2p1S2p1 +3, (or 3 +3, (or 3 bonds)bonds)

Nonmetals Nonmetals & metals& metals

Extracted from Extracted from bauxite orebauxite ore

Al - cansAl - cans

CarbonCarbon S2p2S2p2 + or – 4, 4 + or – 4, 4 bondsbonds

Nonmetals Nonmetals to metalsto metals

Common in life, Common in life, rocks & oresrocks & ores

C – pencils, Si – C – pencils, Si – chips, Pb – wtschips, Pb – wts

NitrogenNitrogen s2p3s2p3 -3, 3 bonds-3, 3 bonds Non-metals, Non-metals, semi-metalssemi-metals

N from air, P N from air, P from from phosphatesphosphates

FertilizersFertilizers

OxygenOxygen S2p4S2p4 -2, 2 bonds-2, 2 bonds Non-metals Non-metals to metalsto metals

O from air, S O from air, S minedmined

Breathing, Breathing, make sulfuric make sulfuric acidacid

HalogensHalogens S2p5S2p5 -1, 1 bond-1, 1 bond Reactive Reactive NonmetalsNonmetals


Cl – bactericideCl – bactericide

F - toothpasteF - toothpaste

Noble Noble GasesGases

S2p6S2p6 0, 0 bonds0, 0 bonds Unreactive Unreactive gasesgases

Isolated from Isolated from airair

He – balloonsHe – balloons

Ar – light bulbsAr – light bulbs

unit 2 atomic/nuclear theory/periodic patterns. unit sequence dayobjectivesassessments activities...

Documents

atomic mass number

odd quiz

rutherford quiz

thomson quiz

avg atomic mass

patterns of atomic radius

cooperative quiz

patterns of periodic