chemistry day 9
TRANSCRIPT
![Page 1: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/1.jpg)
Chemistry Day 9 Monday, September 23rd – Tuesday,
September 24th, 2019
![Page 2: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/2.jpg)
Do-Now Title: “Brainstorm: Unit 1” 1. Write down today’s FLT 2. Draw what an atom looks like according to
Democritus and Dalton 3. Draw what an atom looks like according to J.J.
Thomson 4. Draw what an atom looks like according to Ernest
Rutherford 5. Use one of the pro-talk sentence frames to tell me
something we have learned about atoms or subatomic particles.
6. Underneath your do-now, write “Brainstorm list” and number 1-20
Finished? Take out your planner and table of contents.
![Page 3: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/3.jpg)
![Page 4: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/4.jpg)
FLT • I will be able to calculate the mass
number and number of neutrons in an atom by completing Atoms CN
Standard HS-PS1-8:Developmodelstoillustratethechangesinthecompositionofthenucleusoftheatomandtheenergyreleasedduringtheprocessesoffission,fusion,andradioactivedecay
![Page 5: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/5.jpg)
Distinguishing Among Atoms
![Page 6: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/6.jpg)
Guiding Questions • Whatmakeselementsandisotopesdifferent?• Howcanwecalculatethenumberofneutronsinanatom?
• HowcanIcalculatetheatomicmassofanelement?
• CanIexplainwhychemistsusetheperiodictable?
![Page 7: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/7.jpg)
Recall • An atom’s atomic number (Z) = the number
of protons in the nucleus. Defines element.
![Page 8: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/8.jpg)
Recall • Elementsaredifferentbecausetheycontaindifferentnumbersofprotonsàifyouchangethenumberofprotons,youchangetheelement
![Page 9: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/9.jpg)
Recall • Atoms are
electrically neutral • Protonshavea+1charge
• Whatbalancesthem?• Electronshavea-1charge
• Therefore,protons=electronsinanatom
![Page 10: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/10.jpg)
![Page 11: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/11.jpg)
Groups have similar properties GroupsaretheVERTICALCOLUMNS
![Page 12: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/12.jpg)
Mass Number • Recall:
– Protonshavearelativemassof1
– Neutronshavearelativemassof1
– Electronshavearelativelyinsignificantmass
![Page 13: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/13.jpg)
Mass Number • Massnumber=p++n0• Copy and complete the table below
Nuclide p+ n0 e- Mass #
Oxygen -
10
- 33 42
- 31 15
8 8 1818
![Page 14: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/14.jpg)
Shorthand Notation MassNumber
AtomicNumber
Symbol
![Page 15: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/15.jpg)
Shorthand Notation ■ Find each of these:
a) number of protons
b) number of neutrons
c) number of electronsd) Atomic number
e) Mass Number C 14
6
![Page 16: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/16.jpg)
Shorthand Notation ■ If an element has an atomic number of
34 and a mass number of 78, what is the: a) number of protonsb) number of neutrons
c) number of electronsd) shorthand notation
![Page 17: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/17.jpg)
Isotopes • What was Dalton mistaken about? • Dalton was also wrong about all elements of
the same type being identical
![Page 18: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/18.jpg)
Isotopes • Atoms of the same element can have
different numbers of neutrons.• Thus, different mass numbers.• These are called isotopes.
![Page 19: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/19.jpg)
Isotopes • FrederickSoddy(1877-1956)proposedtheideaofisotopesin1912
• Isotopes=atomsofthesameelementhavingdifferentmasses,duetovaryingnumbersofneutrons.
• SoddywontheNobelPrizeinChemistryin1921forhisworkwithisotopesandradioactivematerials.
![Page 20: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/20.jpg)
Isotopes
• We can also put the mass number after the name of the element: – carbon-12 – carbon-14 – uranium-235
![Page 21: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/21.jpg)
Isotopes Isotope Protons Electrons Neutrons Nucleus
Hydrogen–1
(protium)
1
1
0
Hydrogen-2
(deuterium)
1
1
1
Hydrogen-3
(tritium)
1
1
2
![Page 22: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/22.jpg)
Isotopes
• Elements occur in nature as mixtures of isotopes.
![Page 23: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/23.jpg)
Atomic Mass § Howheavyisanatomofoxygen?§ Itdepends,becausetherearedifferentkindsofoxygenatoms.
§ Wearemoreconcernedwiththeaverageatomicmass.
§ Averageatomicmass=weightedaverageoftheisotopesofagivenelementbasedonthepercentabundanceinnature
![Page 24: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/24.jpg)
Atomic Mass • Each isotope has its own atomic
mass, thus we determine the average from percent abundance.
![Page 25: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/25.jpg)
Calculating Atomic Mass • Multiply the atomic mass of
each isotope by its abundance (expressed as a decimal), then add the results.
• If not told otherwise, the mass of the isotope is expressed in atomic mass units (amu)
![Page 26: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/26.jpg)
Example Anelementhasthefollowingnaturalabundancesandisotopicmasses:90.92%abundancewith19.99amu,0.26%abundancewith20.99amu,and8.82%abundancewith21.99amu.Calculatetheaverageatomicmassofthiselement.Solution:Averageatomicmass=(0.9092×19.99amu)+(0.0026×20.99amu)+(0.0882×21.99amu)Averageatomicmass=20.17amuMakesuretoshowworkandunitsJ
![Page 27: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/27.jpg)
Pair-Share-Respond 1. What is Z? 2. Can atoms of the same element have
different numbers of protons? 3. Discuss all information you can
derive from the shorthand notation pictured
4. Explain how isotopes differ from one another.
5. What is meant by the term “average atomic mass”?
![Page 28: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/28.jpg)
Chemistry Day 10 Wednesday, September 25th – Thursday,
September 26th, 2019
![Page 29: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/29.jpg)
Do-Now Title: “Nuclear Notation Review” 1. Answer the do-now questions on your
worksheet 2. If you finish early, you may start on the back.
Otherwise, it is part of our classwork. You may not work on it once we start our announcements.
Finished? Take out your planner and table of
contents.
![Page 30: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/30.jpg)
FLT • I will be able to describe the three main
types of nuclear radiation by completing Ch. 19 CN A
Standard HS-PS1-8:Developmodelstoillustratethechangesinthecompositionofthenucleusoftheatomandtheenergyreleasedduringtheprocessesoffission,fusion,andradioactivedecay
![Page 31: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/31.jpg)
Ch. 19 Part A: Radiation
![Page 32: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/32.jpg)
Review–AtomicModels
![Page 33: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/33.jpg)
Nucleons and Nuclear Forces
![Page 34: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/34.jpg)
SubatomicParticles• In1932,JamesChadwickdiscoveredtheneutron
• Thiswasimportantinimprovingtheproton-electronatomicmodel
• Newmodel:Theproton-neutronnucleus
![Page 35: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/35.jpg)
Proton-NeutronModel
![Page 36: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/36.jpg)
SubatomicParticles• Wenowhavethreesubatomicparticles:– Protonsp+– Electronse-– Neutronsn0
• Nucleons=subatomicparticleslocatedinthenucleusofatoms(p+andn0)– Nucleonsarecomposedofsmallerparticlescalledquarks
![Page 37: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/37.jpg)
Forces• Therearetwomainforcesatplayinournucleus:
– Electromagneticforce(proton-protonrepulsion)– Strongforce(nucleonssticktogether)
![Page 38: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/38.jpg)
Forces• Notallnucleiarestable
– Positively-chargedprotonscanrepeleachother• StrongNuclearForce=bindsp+andn0togetherinthenucleus
![Page 39: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/39.jpg)
Unstable Nuclei – Strongforce=holdsnucleitogetherovershortdistances
– Largernucleicanbemoreunstable
![Page 40: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/40.jpg)
Nuclear Stability
![Page 41: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/41.jpg)
NuclearStability• StrongNuclearForce
– Thisforcecanonlyactoververyshortdistances– Itisthestrongestattractiveforce(137timesmorethanelectromagnetic)
– Overextremelyshortdistances,thestrongnuclearforceoverridestherepulsionoftheelectromagneticforce
• Lookingattheratioofprotonstoneutronscanhelpusdeterminethestabilityofthenucleus
![Page 42: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/42.jpg)
Band of Stability
• The region on a graph which indicates all stable nuclei when the number of neutrons are compared to the number of protons for all stable nuclei
![Page 43: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/43.jpg)
NuclearStability• Largernuclidestendtobemoreunstable
– Allnuclideswithmorethan83protons(bismuth)areunstable
• Mostnuclideswanta1:1ofneutrons:protons– Heaviernuclidesneedmoreneutrons
![Page 44: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/44.jpg)
Pair-Share-Respond 1. Whatarenucleons?2. Explainthetypesofforcesoccurringwithinanucleus
3. Describetwodifferenttypesofnucleithatareunstable
![Page 45: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/45.jpg)
Radioactivity
![Page 46: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/46.jpg)
Radioactivity
• Howdoesanunstablenucleusreleaseenergy?
![Page 47: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/47.jpg)
Context • MarieCurie(1867-1934)helpeddiscovernewelements(PoloniumandRadium),aswellasradioactiveelements
• Curiestudiedmaterialsthatgaveoffrays,whichshecalledradioactivity
![Page 48: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/48.jpg)
Radiation • Radiation=Rays&particlesemittedbyaradioactivesource
![Page 49: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/49.jpg)
Radiation Radioisotopes=unstableisotopeswhosenucleiundergochangestobecomemorestable
![Page 50: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/50.jpg)
Radioactivity
– Anunstablenucleus“decays”intoanewnucleusbychangingitsnumberofprotonsspontaneously
– Ifthenumberofprotonschanges,isitthesameelementanymore?
![Page 51: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/51.jpg)
Radioactivity – Radioactivedecay=unstablenucleusreleasesenergy/emitsradiation
![Page 52: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/52.jpg)
Types of Radiation
![Page 53: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/53.jpg)
Types of Radiation
What are the three main types of nuclear radiation?
![Page 54: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/54.jpg)
Main Types of Radiation
1. Alpha (α) Radiation 2. Beta (β) Radiation 3. Gamma (Υ) Radiation
![Page 55: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/55.jpg)
Alpha Radiation Alpha radiation = Emits alpha particles (helium) • Mass number decreases by 4, atomic number
decreases by 2
![Page 56: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/56.jpg)
![Page 57: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/57.jpg)
Alpha Radiation Ex/
![Page 58: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/58.jpg)
Beta Radiation
• Beta Radiation = Emits a beta particle (electron) – Mass number stays the same. Atomic number increases by
1.
![Page 59: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/59.jpg)
![Page 60: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/60.jpg)
Beta Radiation Ex/
![Page 61: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/61.jpg)
Gamma Radiation
• Gamma radiation = Emits a high-E photon(gamma ray).
• Tends to accompany other nuclear decay processes
![Page 62: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/62.jpg)
![Page 63: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/63.jpg)
Types of Radiation
• Alphaparticlesaretheleastpenetrating.Gammaraysarethemostpenetrating.
![Page 64: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/64.jpg)
Figure4.2:Thepenetratingpowerofradiation.
© 2003 John Wiley and Sons Publishers
![Page 65: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/65.jpg)
Arethereothertypesofdecay?
α-particleproduction
Spontaneousfission
β-particleproduction
Positronproduction
γ-rayproduction
![Page 66: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/66.jpg)
Positron Production
• Positron = positively charged anti-electron
![Page 67: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/67.jpg)
Pair-Share-Respond 1. Whatareradioisotopes?2. Whatareourthreemaintypesof
radiation?3. Whichtypeisthemostdangerous?4. Whatisemittedinbetadecay?5. Whatisemittedinalphadecay?
![Page 68: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/68.jpg)
Chemistry Day 11 Friday, September 27th, 2019
![Page 69: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/69.jpg)
Do-Now Title: “BrainPOP: Radioactivity” 1. Write down today’s FLT 2. What is your current grade in this class? 3. Is your grade where you want it to be? If not,
what will you do to change it? 4. What is the most difficult part of this class so
far? 5. Define the term “radioisotope”. Even better if
you can do it without referring to the notes. 6. Underneath your do-now, write “brainpop
practice” and number 1-10 Finished? Take out your planner and table of
contents.
![Page 70: Chemistry Day 9](https://reader030.vdocuments.mx/reader030/viewer/2022020702/61f9d2378d112a4ab1377a82/html5/thumbnails/70.jpg)
Add to do-now paper: 1. Use a pro-talk sentence frame to tell me
something about radioactivity. 2. You have isolated one kilogram of pure Mobium,
a new radioactive substance. When Mobium decays, it becomes ordinary iron. You have a sample of 25 grams.
a. You wrap the sample in paper, and observe that radiation is no longer detectable. What kind of radiation is it (possibly) emitting?
b. After 6 hours, you notice that only 12.5 grams remain. Explain what happened.
3. List three examples of radioactive elements. 4. What are some risks of studying radioactive
elements?