Presentation on theme: "Electron Energy Levels"— Presentation transcript:
1 Electron Energy Levels Chapter 4: AtomsElements & SymbolsThe Periodic TableAtomic StructureIsotopesElectron Energy LevelsPeriodic Trends
2 Atomic Symbols Each element is assigned a unique symbol NitrogenHydrogenBromineNickelAluminumEach element is assigned a unique symbol1-2 letters; 1st is capitalized
3 Atomic Symbols Each element is assigned a unique symbol. aluminum Al potassium Kbarium Ba nickel Nicarbon C nitrogen Nchlorine Cl oxygen Ohydrogen H radon Rnhelium He titanium Tigold Au uranium UEach is 1-2 letters and the first is capitalized.Symbol may not match the name - The original name is often of latin or greek origin.
4 Atomic Symbols Sodium (Natrium) Potassium (Kalium) Silver (Argentum) Lead(Plumbum)Iron(Ferrum)Gold (Aurum)The original name is often of Latin or Greek origin
5 Atomic SymbolsSome of the elements whose symbols are derived from other languagesCopper (Cuprum from Cyprus) CuGold (Aurum Shining Dawn) AuIron (Ferrum) FeLead (Plumbum) PbPotassium (Kalium) KSilver (Argentum) AgMercury (Hydrargyrum Liquid silver) HgSodium (Natrium) NaTin (Stannum) SnTungsten (Wolframium) W
6 Atomic SymbolsCarbonCalciumCobaltCopper (Cu)ChlorineChromiumElements with same starting letter, get second letter added to the symbol
7 Atomic SymbolsFor elements having the same starting letter, a second letter is added to the symbol. This letter is one of the following letters in the elements name and is always in lower case.Carbon C Californium CfCalcium Ca Cadmium CdCerium Ce Cesium CsChlorine Cl Chromium CrCobalt Co Curium Cm
8 “Properties of the elements vary in a periodic manner.” Modern periodic tableMendeleev, 1871“Properties of the elementsvary in a periodic manner.”I A II A III A IV A V A VI A VIIA VIIIAHLiNaCsRbKTlHgAuHfLaBaFrPtIrOsReWTaHeRnAtPoBiPbBeMgSrCaCdAgZrYPdRhRuTcMoNbAcRaZnCuTiScNiCoFeMnCrVInXeITeSbSnGaKrBrSeAsGeAlArClSPSiBNeFONC1234567The periodic tablehelps us understandbehavior,reactionspropertiesof the elements.III B IVB V B VIB VIIB VIII B IB IIBCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
9 A row or period Periods are assigned numbers 1 2 3 4 5 6 7 H He Li Be CNOFNeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
10 Common group names Noble gases Alkali Metals Halogens Alkaline Earth MetalsI AVIIIAChalcogensHHeII AIII A IV A V A VI A VIIATransition MetalsLiBeBCNOFNeNaMgAlSiPSClArIII B IVB V B VIB VIIB VIII B IB IIBKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrLanthanidesRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcGdCmTbBkSmPuEuAmNdUPmNpCeThPrPaYbNoLuLrErFmTmMdDyCfHoEsActinides
11 Why do we have those rows on the bottom? LiNaCsRbKLaBaFrBeMgSrCaYAcRaScTlHgAuHfPtIrOsReWTaHeRnAtPoBiPbCdAgZrPdRhRuTcMoNbZnCuTiNiCoFeMnCrVInXeITeSbSnGaKrBrSeAsGeAlArClSPSiBNeFONCThis arrangement takes toomuch space and is hard to read.GdCmTbBkSmPuEuAmNdUPmNpCeThPrPaYbNoLuLrErFmTmMdDyCfHoEs
12 Names & Symbols Know the names & symbols 1 2 3 4 5 6 7 H He Li Be B C FNeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
13 Metals Lustrous, malleable and ductile. Conductors (heat & electricity)Solids at room temp (except Hg)Lose electrons to non-metals.HHeLiBeBCNOFNeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
14 Non-metals Gas, liquid, solid (dull, brittle) HHeLiBeAtTeAsSiBCNOFNeNaMgAlPSClArGas, liquid, solid (dull, brittle)Poor conductors = InsulatorsMany are diatomic molecules.Gain e’s from metalsShare e’s with other non-metalsKCaScTiVCrMnFeCoNiCuZnGaGeSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
15 Metaloids Intermediate properties Semi conductors H He Li Be B C N O F NeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeIntermediate propertiesSemi conductorsCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr3 - 11
16 Metals Non-metals Metaloids H He Li Be B C N O F Ne Na Mg Al Si P S Cl ArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
17 Elemental states at room temperature HSolidLiquidGasHeLiBeBCNOFNeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr3 - 13Chemeketa Community College: Chemistry for Allied Health
18 Atom - The smallest unit of an element that is still that element. A model of matterAtom - The smallest unit of an element that is still that element.ie. Aluminum (Al)Molecule -The smallest unit of a pure substance that is still that substance.May contain > 1 atom or element.ie. Water (H2O)
19 protons Structure of the atom & neutrons Nucleus Small, dense, + charge in the center of an atom.+containsprotons+++++&neutrons
20 Rutherford’s Gold-Foil Experiment 99% of + particles aimed at gold went straight through.A few were deflected.A few bounced backConclusion:Atoms are mostly empty space.Atoms have a small, dense nucleus with + charge.
21 - charged particles that surround the nucleus. Structure of the atomNucleus (+)Electrons- charged particles that surround the nucleus.Electrons moved around nucleus in orbitals.
22 Structure of the atom The nucleus is a small part of an atom. If the nucleus was the sizeof a marble, the atom wouldfill a football stadium.The nucleus would weighover 10,000 tons.
23 X - - - - - - The atomic symbol A = Atomic mass (amu) = # protons + # neutrons--XA--Z++Z = Atomic number= # protons = # electrons-++++-
24 X The atomic symbol C = Charge A = Atomic mass = + or - values A C Z # = # p + # nC = Charge= + or - valuesXACZ#Z = Atomic ## p = # e# = Number of atoms in a formula.
25 X - - - - - - 6 The atomic symbol A = Atomic mass 12 Z = Atomic number = # protons + # neutrons66--X12--6++Z = Atomic number= # protons = # electrons-++++-
26 C - - - - - - 6 The atomic symbol A = Atomic mass 12 Z = Atomic number = # protons + # neutrons--C12--6++Z = Atomic number= # protons = # electrons-++++-
27 Na Sodium The atomic symbol A = Atomic mass = p + n = 23 C = Charge 23 = +11112231+Na11# = 1 atom in formula.Z = Atomic # = p = 11Sodium
28 Why is the atomic weight on the tables not a whole #? 47Atomic numberName of the elementElemental SymbolSilverAg107.87Atomic mass (weight)Atomic weight = The average, relative mass of an atom in an element.
29 - - - Isotopes of Hydrogen H H H + + + Isotopes = Atoms of the same element but having different masses.12131HHH---+++Protium99.99%TritiumTrace %Deuterium0.01%
30 Average Atomic weight of Hydrogen Isotopes of HydrogenIsotopes = Atoms of the same element but having different masses.12131HHH---+++Average Atomic weight of Hydrogen= amu
31 Average Atomic weight of C= 12.011 amu Isotopes of Carbon121314CCC666--------+++-+++++++++--++++++-------98.89%1.11%Trace %Average Atomic weight of C= amu
32 So falls apart (decays) Giving radioactive particles Radioactive IsotopesC61431HH-3C-14zzz+-+-Nucleus is unstableSo falls apart (decays)Giving radioactive particles
33 Cl Cl Average Atomic Mass 37 35 17 17 75.8% 24.2% (75.8)35 + (24.2)37 + (24.2)37= amu100
34 The atomic symbol & isotopes Complete the table:ProtonsNeutronsElectrons3115P15161513856Ba56825623892U9214692
35 Atomic Structure Be 4 9 4 5 4 Cl 17 37 17 20 17 Si 14 28 14 14 14 Complete the table:SymbolAtomic#MassProtonsNeutronsElectronsBe49454Cl1737172017Si1428141414
36 Electronic arrangement A new layer isadded for each row or period in the table.
37 fill layers around nucleus Electron arrangement2412MgElectronsfill layers around nucleusLow High321882Shells = Energy levels
41 H He Be Li Ne Mg Ar Na 1 4 2 9 7 4 3 IA IIA VIIIA 20 10 2, 1 2, 2 2, 8 2412Mg4018Ar2311Na2, 8, 82, 8, 12, 8, 2
42 H Be Li B Mg Al Na 1 9 7 4 3 1 Valence electrons Where most chemical Reactions occur.1H2394Be73Li115B2, 32, 12, 22412Mg2713Al2311Na2, 8, 32, 8, 12, 8, 2
43 H He Be Li Ne Mg Ar Na Octet Rule 1 4 2 9 4 7 3 1 8 2 20 10 2, 1 2, 2 2, 82412Mg4018Ar2311Na2, 8, 82, 8, 12, 8, 2
44 The octet ruleAtoms are most stable if they have a filled or empty outer layer of electrons.Except for H and He, a filled layer contains 8 electrons - an octet.Atoms gain, lose or share electrons to make a filled or empty outer layer.Atoms gain, lose or share electrons based on what is easiest.
45 Rules for electron Placement An atom is like an inverted pyramid. As you get farther from the nucleus, there is more room for electrons.1st level holds 2 e’s.2nd level holds 8 e’s.3rd level holds 18 e’s.4th level holds 32 e’s.etc....2 e-8 e-18 e-32 e-+
46 Each shell (floor of the Hotel) Hotel ModelEach shell (floor of the Hotel)Has subshells (s,p,d,f)fn = 4 (4th floor)dpsdn = 3 (3rd floor)psn = 2 (2nd floor)psn = 1 (1st floor)s+
47 OrbitalsEach subshell contains orbitals which can hold a maximum of two electronsp (3)d (5)s (1)f (7)
48 The Aufbau principle Hund’s Rule Electrons fill from the low high. fill n = 1before n = 2 ,fill s before p ...n = 4n = 3n = 2Hund’s Rulen = 1+Electrons don’t share same orbital unless they need to.(i.e. no pairing until each orbital of the set has an electron)
49 Major trends in electron filling 5p4d4f4s4p3d3s3p2s2p1sMajor trends in electron fillingExceptions to Hotel Model:Fill 4s before 3dFill 5d before 4 fFill 5s before 4dFill 6d before 5 fThis is whytransition metalsare assigned asB group elements.
50 Rules for filling the dormitory In this analogy, each floor is equivalent to an energy level and each room is equivalent to an orbital. The students are the electrons.1. Students must be placed in the lowest room of the lowest floor that is available.2. Students may not be paired until each room of a given set is occupied.3. No room can hold more than 2 students.4. The 2 students in a room must be in opposite directions5. There can never be more than 8 students in the highest occupied floor, no matter how many rooms are available.
51 Applying the rules. Solve the following problem: A student enrolls in the Manganese dormitory (25 student capacity). If she is the last one admitted to the dorm, what floor is she on and which room is she in? Does she have a room mate?
52 Electronic Configuration Chemists often use a shorthand notation to show where the electrons are in an atom.example: Neon: 20 Ne 1s2 2s2 2p610Phosphorus 31 P 1s2 2s2 2p6 3s2 3p315The periodic table only shows the outer electrons, using the symbol for the inert gas that immediately precedes the element.ex. Phosphorus [Ne] 3s2 3p3
53 *Orbital DiagramsAs helpful as electronic configurations are, they only tell you the total number of electrons in each energy levels’ sublevels, not the number in the orbitals themselves.Orbital diagrams take it one step further.Phosphorus1s s22p63s23p3
57 Classification by sublevels pHHedLiBeBCNOFNeNaMgAlSiPSClArKCaScHfZrTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLsTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLufThPaUNpPuAmCmBkCfEsFmMdNoLr3 - 25
58 Using the periodic table to find sublevels 1HLiNaCsRbKBaFrHeBeMgSrCaRap22TlRnAtPoBiPbInXeITeSbSnGaKrBrSeAsGeAlArClSPSiBNeFONC3d343ScTiVCrMnFeCoNiCuZn454YZrNbMoTcRuRhPdAgCd55LaHfTaWReOsIrPtAuHg666Ac74GdCmTbBkSmPuEuAmNdUPmNpCeThPrPaYbNoLuLrErFmTmMdDyCfHoEsf5
59 Inner vs. valence electrons Where mostreactionsoccur.Inner electronsNot much happenshere under normalconditions.
60 The Continuous Spectrum When sunlight (white light) is passed thru a prism, a continuous rainbow of colors is observed.There appears to be light of every color in sunlight.
61 Electromagetic Spectrum The Continuous SpectrumElectromagetic SpectrumOverhead # 26 from chapter 7.
62 The Continuous Spectrum Actually, most light waves cannot be seen by the human eye.The visible spectrum (violet to red) is a very small percentage of the entire electro- magnetic spectrum.Shorter wave length light is high energy.(Gamma rays, X-rays, UV, etc..)Larger wave length light is low energy.(IR, Microwaves, Radio, etc..)
63 The Discrete Spectrum !But when light from elements is passed thru a prism, a continuous spectrum is not observed.From the red glow of hydrogen, 4 lines emerged.
64 Excitation of electrons 1 _____2 _____3 _____4 _____5 _____6 _____1 _____2 _____3 _____4 _____5 _____6 _____1H410 nm434 nm486 nmE656 nmAdd Energy to kick e- to higher levelEnergy is given back when e- falls back to lower levelSome of these discrete Quantities (Quanta) of Energy appear as colors
65 Emission Spectrum of Hydrogen Explanation of 4 line spectrum of Hydrogen: (10:49min)
67 First ionization energy Periodic trendsCertain properties of the elements exhibit a gradual change as we go either across a period or down a group.Knowing these trends can help in our understanding of chemical properties -We’ll look briefly atthese trends for therepresentativeelements.Valence EletronsAtomic sizeFirst ionization energyElectron affinityElectronegativity
69 H Li Na K H Li Electron-Dot Symbols (Lewis Symbols) Show only Valence 1HHShow onlyValenceElectrons73LiLiNa2311NaK
70 He O F N Si S P Ca H Li C Na K Se Periodic trends Electron-Dot Symbols 18Electron-Dot SymbolsHHe234567COLiBNFNeBeSiAlSClArMgPNaKrCaGaAsSeBrKGe
71 Periodic trends Atomic Size Atoms get smaller as you go across a period.BaSrCaMgBeTlInGaAlBPbSnGeSiCCsRbKNaLiBiSbAsPNTeSeSIBrClFHAtomsgetlargerasyougodownagroup.
72 Periodic trends Atomic Size Atoms get larger as you go down a group. A new shell is being added which is located further from the nucleus.Atoms get smaller as you go across a period.There are more protons being added to the nucleus as electrons are added to the outer shell.This higher positive charge attracts the electrons more strongly, making the atom smaller. (Air traffic control analogy)
73 First ionization energy Periodic trendsFirst ionization energyThe energy required to remove the first electron from a neutral atom.AtIBrClPoTeSeSBiSbAsPPbSnGeSiFONTlNaCsRbKBaMgSrCaInGaAlHLiBeBC4 - 50Chemeketa Community College: Chemistry for Allied Health
74 Periodic trends Electron affinity Energy released when an atom gains an e-.AtIBrClPoTeSeSBiSbAsPPbSnGeSiFONTlNaCsRbKBaMgSrCaInGaAlHLiBeBC4 - 50Chemeketa Community College: Chemistry for Allied Health
75 Periodic trends Electronegativity Relative ability of atoms to attract electrons when they form bonds.HLiBeBCNOFNaMgAlSiPSClKCaGaGeAsSeBrRbSrInSnSbTeICsBaTlPbBiPoAtChemeketa Community College: Chemistry for Allied Health4 - 50
76 Periodic trends Summary of trends. As atomic size decreases First ionization energy increases.Electrons are harder to remove.Adding more electrons is easier.SummaryMetals are larger so tend to lose electrons.Non-metals are smaller so tend to gain electrons.